Money

Money is any object or record that is generally accepted as payment for goods and services and repayment of debts in a given socio-economic context or country. The main functions of money are distinguished as: a medium of exchange; a unit of account; a store of value; and, occasionally in the past, a standard of deferred payment.  Any kind of object or secure verifiable record that fulfills these functions can be considered money.

Money is historically an emergent market phenomenon establishing a commodity money, but nearly all contemporary money systems are based on fiat money.[4] Fiat money, like any check or note of debt, is without intrinsic use value as a physical commodity. It derives its value by being declared by a government to be legal tender; that is, it must be accepted as a form of payment within the boundaries of the country, for "all debts, public and private"[citation needed]. Such laws in practice cause fiat money to acquire the value of any of the goods and services that it may be traded for within the nation that issues it.

The money supply of a country consists of currency (banknotes and coins) and bank money (the balance held in checking accounts and savings accounts). Bank money, which consists only of records (mostly computerized in modern banking), forms by far the largest part of the money supply in developed nations.
 History
A 640 BC one-third stater electrum coin from Lydia.
Main article: History of money

The use of barter-like methods may date back to at least 100,000 years ago, though there is no evidence of a society or economy that relied primarily on barter.[9] Instead, non-monetary societies operated largely along the principles of gift economics and debt.[10][11] When barter did in fact occur, it was usually between either complete strangers or potential enemies.[12]

Many cultures around the world eventually developed the use of commodity money. The shekel was originally a unit of weight, and referred to a specific weight of barley, which was used as currency.[13] The first usage of the term came from Mesopotamia circa 3000 BC. Societies in the Americas, Asia, Africa and Australia used shell money – often, the shells of the money cowry (Cypraea moneta L. or C. annulus L.). According to Herodotus, the Lydians were the first people to introduce the use of gold and silver coins.[14] It is thought by modern scholars that these first stamped coins were minted around 650–600 BC.[15]
Song Dynasty Jiaozi, the world's earliest paper money

The system of commodity money eventually evolved into a system of representative money.[citation needed] This occurred because gold and silver merchants or banks would issue receipts to their depositors – redeemable for the commodity money deposited. Eventually, these receipts became generally accepted as a means of payment and were used as money. Paper money or banknotes were first used in China during the Song Dynasty. These banknotes, known as "jiaozi", evolved from promissory notes that had been used since the 7th century. However, they did not displace commodity money, and were used alongside coins. In the 13th century, paper money became known in Europe through the accounts of travelers, such as Marco Polo and William of Rubruck.[16] Marco Polo's account of paper money during the Yuan Dynasty is the subject of a chapter of his book, The Travels of Marco Polo, titled "How the Great Kaan Causeth the Bark of Trees, Made Into Something Like Paper, to Pass for Money All Over his Country."[17] Banknotes were first issued in Europe by Stockholms Banco in 1661, and were again also used alongside coins. The gold standard, a monetary system where the medium of exchange are paper notes that are convertible into pre-set, fixed quantities of gold, replaced the use of gold coins as currency in the 17th-19th centuries in Europe. These gold standard notes were made legal tender, and redemption into gold coins was discouraged. By the beginning of the 20th century almost all countries had adopted the gold standard, backing their legal tender notes with fixed amounts of gold.

After World War II, at the Bretton Woods Conference, most countries adopted fiat currencies that were fixed to the US dollar. The US dollar was in turn fixed to gold. In 1971 the US government suspended the convertibility of the US dollar to gold. After this many countries de-pegged their currencies from the US dollar, and most of the world's currencies became unbacked by anything except the governments' fiat of legal tender and the ability to convert the money into goods via payment.
Etymology

The word "money" is believed to originate from a temple of Hera, located on Capitoline, one of Rome's seven hills. In the ancient world Hera was often associated with money. The temple of Juno Moneta at Rome was the place where the mint of Ancient Rome was located.[18] The name "Juno" may derive from the Etruscan goddess Uni (which means "the one", "unique", "unit", "union", "united") and "Moneta" either from the Latin word "monere" (remind, warn, or instruct) or the Greek word "moneres" (alone, unique).

In the Western world, a prevalent term for coin-money has been specie, stemming from Latin in specie, meaning 'in kind'.
Functions: In the past, money was generally considered to have the following four main functions, which are summed up in a rhyme found in older economics textbooks: "Money is a matter of functions four, a medium, a measure, a standard, a store." That is, money functions as a medium of exchange, a unit of account, a standard of deferred payment, and a store of value.[5] However, modern textbooks now list only three functions, that of medium of exchange, unit of account, and store of value, not considering a standard of deferred payment as a distinguished function, but rather subsuming it in the others.[4][20][21]

There have been many historical disputes regarding the combination of money's functions, some arguing that they need more separation and that a single unit is insufficient to deal with them all. One of these arguments is that the role of money as a medium of exchange is in conflict with its role as a store of value: its role as a store of value requires holding it without spending, whereas its role as a medium of exchange requires it to circulate.[5] Others argue that storing of value is just deferral of the exchange, but does not diminish the fact that money is a medium of exchange that can be transported both across space and time.[22] The term 'financial capital' is a more general and inclusive term for all liquid instruments, whether or not they are a uniformly recognized tender.
Medium of exchange
Main article: Medium of exchange

When money is used to intermediate the exchange of goods and services, it is performing a function as a medium of exchange. It thereby avoids the inefficiencies of a barter system, such as the 'double coincidence of wants' problem.
Unit of account
Main article: Unit of account

A unit of account is a standard numerical unit of measurement of the market value of goods, services, and other transactions. Also known as a "measure" or "standard" of relative worth and deferred payment, a unit of account is a necessary prerequisite for the formulation of commercial agreements that involve debt. To function as a 'unit of account', whatever is being used as money must be:

    Divisible into smaller units without loss of value; precious metals can be coined from bars, or melted down into bars again.
    Fungible: that is, one unit or piece must be perceived as equivalent to any other, which is why diamonds, works of art or real estate are not suitable as money.
    A specific weight, or measure, or size to be verifiably countable. For instance, coins are often milled with a reeded edge, so that any removal of material from the coin (lowering its commodity value) will be easy to detect.

Store of value
Main article: Store of value

To act as a store of value, a money must be able to be reliably saved, stored, and retrieved – and be predictably usable as a medium of exchange when it is retrieved. The value of the money must also remain stable over time. Some have argued that inflation, by reducing the value of money, diminishes the ability of the money to function as a store of value.[4]
Standard of deferred payment
Main article: Standard of deferred payment

While standard of deferred payment is distinguished by some texts,[5] particularly older ones, other texts subsume this under other functions.[4][20][21] A "standard of deferred payment" is an accepted way to settle a debt – a unit in which debts are denominated, and the status of money as legal tender, in those jurisdictions which have this concept, states that it may function for the discharge of debts. When debts are denominated in money, the real value of debts may change due to inflation and deflation, and for sovereign and international debts via debasement and devaluation.
Measure of value

Money acts as a standard measure and common denomination of trade. It is thus a basis for quoting and bargaining of prices. It is necessary for developing efficient accounting systems. But its most important usage is as a method for comparing the values of dissimilar objects.

Twitter

Twitter is an online social networking service and microblogging service that enables its users to send and read text-based messages of up to 140 characters, known as "tweets".

Twitter was created in March 2006 by Jack Dorsey and by July, the social networking site was launched. The service rapidly gained worldwide popularity, with over 500 million registered users as of 2012, generating over 340 million tweets daily and handling over 1.6 billion search queries per day.[8][10][11] Since its launch, Twitter has become one of the ten most visited websites on the Internet, and has been described as "the SMS of the Internet."[7][12] Unregistered users can read tweets, while registered users can post tweets through the website interface, SMS, or a range of apps for mobile devices.[13]

Twitter Inc. is based in San Francisco, with additional servers and offices in New York City, Boston, and San Antonio.
 History
Creation and initial reaction
A blueprint sketch, c. 2006, by Jack Dorsey, envisioning an SMS-based social network.

Twitter's origins lie in a "daylong brainstorming session" held by board members of the podcasting company Odeo. Dorsey, then an undergraduate student at New York University, introduced the idea of an individual using an SMS service to communicate with a small group.[14][15] The original project code name for the service was twttr, an idea that Williams later ascribed to Noah Glass,[16] inspired by Flickr and the five-character length of American SMS short codes. The developers initially considered "10958" as a short code, but later changed it to "40404" for "ease of use and memorability."[17] Work on the project started on March 21, 2006, when Dorsey published the first Twitter message at 9:50 PM Pacific Standard Time (PST): "just setting up my twttr".[1]

    "...we came across the word 'twitter', and it was just perfect. The definition was 'a short burst of inconsequential information,' and 'chirps from birds'. And that's exactly what the product was." – Jack Dorsey[18]

The first Twitter prototype was used as an internal service for Odeo employees and the full version was introduced publicly on July 15, 2006.[9] In October 2006, Biz Stone, Evan Williams, Dorsey, and other members of Odeo formed Obvious Corporation and acquired Odeo and all of its assets – including Odeo.com and Twitter.com – from the investors and shareholders.[19] Williams fired Glass who was silent about his part in Twitter's startup until 2011.[20] Twitter spun off into its own company in April 2007.[21]

The tipping point for Twitter's popularity was the 2007 South by Southwest Interactive (SXSWi) conference. During the event, Twitter usage increased from 20,000 tweets per day to 60,000.[22] "The Twitter people cleverly placed two 60-inch plasma screens in the conference hallways, exclusively streaming Twitter messages," remarked Newsweek's Steven Levy. "Hundreds of conference-goers kept tabs on each other via constant twitters. Panelists and speakers mentioned the service, and the bloggers in attendance touted it."[23]

Reaction at the conference was highly positive. Blogger Scott Beale said that Twitter "absolutely rul[ed]" SXSWi. Social software researcher danah boyd said Twitter "own[ed]" the conference.[24] Twitter staff received the festival's Web Award prize with the remark "we'd like to thank you in 140 characters or less. And we just did!"[25]

The first unassisted off-Earth Twitter message was posted from the International Space Station by NASA astronaut T. J. Creamer on January 22, 2010.[26] By late November 2010, an average of a dozen updates per day were posted on the astronauts' communal account, @NASA_Astronauts. NASA has also hosted over 25 "tweetups", events that provide guests with VIP access to NASA facilities and speakers with the goal of leveraging participants' social networks to further the outreach goals of NASA.

In August 2010, the company appointed Adam Bain from News Corp.'s Fox Audience Network as president of revenue.[27]

On September 14, 2010, Twitter launched a redesigned site[28] including a new logo.[citation needed]
Growth

The company experienced rapid growth. It had 400,000 tweets posted per quarter in 2007. This grew to 100 million tweets posted per quarter in 2008. In February 2010, Twitter users were sending 50 million tweets per day.[29] By March 2010, the company recorded over 70,000 registered applications.[30] As of June 2010, about 65 million tweets were posted each day, equaling about 750 tweets sent each second, according to Twitter.[31] As of March 2011, that was about 140 million tweets posted daily.[32] As noted on Compete.com, Twitter moved up to the third-highest-ranking social networking site in January 2009 from its previous rank of twenty-second.[33]
Jack Dorsey, a co-founder and the chairman of Twitter, in 2009

Twitter's usage spikes during prominent events. For example, a record was set during the 2010 FIFA World Cup when fans wrote 2,940 tweets per second in the thirty-second period after Japan scored against Cameroon on June 14, 2010. The record was broken again when 3,085 tweets per second were posted after the Los Angeles Lakers' victory in the 2010 NBA Finals on June 17, 2010,[34] and then again at the close of Japan's victory over Denmark in the World Cup when users published 3,283 tweets per second.[35] The record was set again during the 2011 FIFA Women's World Cup Final between Japan and the United States, when 7,196 tweets per second were published.[36] When American singer Michael Jackson died on June 25, 2009, Twitter servers crashed after users were updating their status to include the words "Michael Jackson" at a rate of 100,000 tweets per hour.[37] The current record as of January 1, 2013, was set by all citizens of the Japan Standard Time Zone as the new year began, reaching a record of 33,388 tweets per second (and hence beating the previous record of 25,088, also set by Japan after a television screening of the movie "Castle In The Sky").[38]

Twitter acquired application developer Atebits on April 11, 2010. Atebits had developed the Apple Design Award-winning Twitter client Tweetie for the Mac and iPhone. The application, now called "Twitter" and distributed free of charge, is the official Twitter client for the iPhone, iPad and Mac.[39]

From September through October 2010, the company began rolling out "New Twitter", an entirely revamped edition of twitter.com. Changes included the ability to see pictures and videos without leaving Twitter itself by clicking on individual tweets which contain links to images and clips from a variety of supported websites including YouTube and Flickr, and a complete overhaul of the interface, which shifted links such as '@mentions' and 'Retweets' above the Twitter stream, while 'Messages' and 'Log Out' became accessible via a black bar at the very top of twitter.com. As of November 1, 2010, the company confirmed that the "New Twitter experience" had been rolled out to all users.

On April 5, 2011, Twitter tested a new homepage and phased out the "Old Twitter."[40] However, a glitch came about after the page was launched, so the previous "retro" homepage was still in use until the issues were resolved; the new homepage was reintroduced on April 20.[41][42]

On December 8, 2011, Twitter overhauled its website once more to feature the "Fly" design, which the service says is easier for new users to follow and promotes advertising. In addition to the Home tab, the Connect and Discover tabs were introduced along with a redesigned profile and timeline of Tweets. The site's layout has been compared to that of Facebook.[43][44]

On February 21, 2012, it was announced that Twitter and Yandex agreed to a partnership. Yandex, a Russian search engine, finds value within the partnership due to Twitter’s real time news feeds. Twitter’s director of business development explained that it is important to have Twitter content where Twitter users go.[45]

On March 21, 2012, Twitter celebrated its sixth birthday while also announcing that it has 140 million users and sees 340 million tweets per day. The number of users is up 40% from their September 2011 number, which was said to have been at 100 million at the time.[46]

In April 2012, Twitter announced that it was opening an office in Detroit, with the aim of working with automotive brands and advertising agencies.[47] Twitter also expanded its office in Dublin.[48]

On June 4, 2012, Twitter announced the purchase of Washington, D.C. based web design agency Nclud. Upon the purchase, Nclud's co-founder and director of brand experience, Martin Ringlein, was named Twitter's new design manager.[49] On June 5, a modified logo was unveiled through the company blog, removing the text to showcase the slightly redesigned bird as the sole symbol of Twitter.[50]

On October 5, 2012, Twitter acquired a video clip company called Vine that launched in January 2013.[51][52] Twitter released Vine as a standalone app that allows users to create and share six-second looping video clips on January 24, 2013. Vine videos shared on Twitter are visible directly in users' Twitter feeds.[53] Due to an influx of inappropriate content, it is now rated 17+ in Apple's app store.[54]

On December 18, 2012, Twitter announced it had surpassed 200 million monthly active users. Twitter hit 100 million monthly active users in September 2011.[55]
Leadership

As chief executive officer, Dorsey saw the startup through two rounds of capital funding by the venture capitalists who backed the company.[56]

On October 16, 2008,[57] Williams took over the role of CEO, and Dorsey became chairman of the board.[58]

On October 4, 2010, Williams announced that he was stepping down as CEO. Dick Costolo, formerly Twitter's chief operating officer, became CEO. According to a Twitter blog, dated October 4, 2010, Williams was to stay[dated info] with the company and "be completely focused on product strategy."[dated info][59]

According to The New York Times, "Mr. Dorsey and Mr. Costolo forged a close relationship" when Williams was away.[60] According to PC Magazine, Williams was "no longer involved in the day-to-day goings on at the company". He is focused on developing a new startup, but he became a member of Twitter's board of directors, and promised to "help in any way I can". Stone is still with Twitter but is working with AOL as an "advisor on volunteer efforts and philanthropy".[61]

Dorsey rejoined Twitter in March 2011, as executive chairman focusing on product development. His time is split with Square (where he is CEO), whose offices are within walking distance of Twitter's in San Francisco.[60]

In September 2011, board members and investors Fred Wilson and Bijan Sabet resigned from Twitter's Board of Directors.[62]

In October 2012, Twitter announced it had hired Google executive Matt Derella to become their new director of business agency development.[63]
Logo

Twitter has become internationally identifiable by its signature bird logo. The original logo was in use from its launch in March 2006 until September 2010. A slightly modified version succeeded the first style when the website underwent its first redesign.

On February 27, 2012, a tweet from an employee that works on the company's platform and API discussed the evolution of the "Larry the Bird" logo with Twitter's creative director and it was revealed that it was named after Larry Bird of the NBA's Boston Celtics fame. This detail had previously been confirmed when the Boston Celtics' director of interactive media asked Twitter co-founder Biz Stone about it in August 2011.[64]

On June 5, 2012, Twitter unveiled its third logo redesign, replacing Larry the Bird with an updated icon simply named as the "Twitter Bird." As of this logo revision, the word "Twitter" and the lowercase letter "t" are no longer used, with the bird becoming the sole symbol for the company's branding.[65] According to Douglas Bowman, designer of Twitter, the new logo resembles a Mountain Bluebird.[66]

    The original logo, used from 15 July 2006 until 14 September 2010.

    The second logo, used from 14 September 2010 until 5 June 2012.

    The third and current logo, used since 5 June 2012.

Features
Tweets
The Twitter account page for Wikipedia, demonstrating the account-customized timeline view showing tweets in reverse chronological order

Tweets are publicly visible by default, but senders can restrict message delivery to just their followers. Users can tweet via the Twitter website, compatible external applications (such as for smartphones), or by Short Message Service (SMS) available in certain countries.[67] While the service is free, accessing it through SMS may incur phone service provider fees.[citation needed]

Users may subscribe to other users' tweets – this is known as following and subscribers are known as followers[68] or tweeps a portmanteau of Twitter and peeps.[69] The users can also check the people who are un-subscribing them on Twitter better known as unfollowing via various services.[70] In addition, users have the capability to block those who have followed them.

Twitter allows users the ability to update their profile by using their mobile phone either by text messaging or by apps released for certain smartphones and tablets.[71]

Twitter has been compared to a web-based Internet Relay Chat (IRC) client.[72] In a 2009 Time essay, technology author Steven Johnson described the basic mechanics of Twitter as "remarkably simple":[73]

    As a social network, Twitter revolves around the principle of followers. When you choose to follow another Twitter user, that user's tweets appear in reverse chronological order on your main Twitter page. If you follow 20 people, you'll see a mix of tweets scrolling down the page: breakfast-cereal updates, interesting new links, music recommendations, even musings on the future of education.

Content
Content of Tweets according to Pear Analytics
  News (3.6%)
  Spam (3.8%)
  Self-promotion (5.9%)
  Pointless babble (40.1%)
  Conversational (37.6%)
  Pass-along value (8.7%)

San Antonio-based market-research firm Pear Analytics analyzed 2,000 tweets (originating from the US and in English) over a two-week period in August 2009 from 11:00 AM to 5:00 PM (CST) and separated them into six categories:[74]

    Pointless babble – 40%
    Conversational – 38%
    Pass-along value – 9%
    Self-promotion – 6%
    Spam – 4%
    News – 4%

Social networking researcher danah boyd responded to the Pear Analytics survey by arguing that what the Pear researchers labelled "pointless babble" is better characterized as "social grooming" and/or "peripheral awareness" (which she explains as persons "want[ing] to know what the people around them are thinking and doing and feeling, even when co-presence isn’t viable").[75]
Format

Users can group posts together by topic or type by use of hashtags – words or phrases prefixed with a "#" sign. Similarly, the "@" sign followed by a username is used for mentioning or replying to other users.[76] To repost a message from another Twitter user, and share it with one's own followers, the retweet function is symbolized by "RT" in the message.[citation needed]

In late 2009, the "Twitter Lists" feature was added, making it possible for users to follow (as well as mention and reply to) ad-hoc lists of authors instead of individual authors.[68][77]

Through SMS, users can communicate with Twitter through five gateway numbers: short codes for the United States, Canada, India, New Zealand, and an Isle of Man-based number for international use. There is also a short code in the United Kingdom which is only accessible to those on the Vodafone, O2[78] and Orange[79] networks. In India, since Twitter only supports tweets from Bharti Airtel,[80] an alternative platform called smsTweet[81] was set up by a user to work on all networks.[82] A similar platform called GladlyCast[83] exists for mobile phone users in Singapore, Malaysia and the Philippines.[citation needed]

The tweets were initially set to a 140-character limit for compatibility with SMS messaging, introducing the shorthand notation and slang commonly used in SMS messages. The 140-character limit has also increased the usage of URL shortening services such as bit.ly, goo.gl, and tr.im, and content-hosting services, such as Twitpic, memozu.com and NotePub to accommodate multimedia content and text longer than 140 characters. Twitter uses its own t.co domain for automatic shortening of all URLs posted on its website.[84]
Trending topics

A word, phrase or topic that is tagged at a greater rate than other tags is said to be a trending topic. Trending topics become popular either through a concerted effort by users or because of an event that prompts people to talk about one specific topic.[85] These topics help Twitter and their users to understand what is happening in the world.[86]

Trending topics are sometimes the result of concerted efforts by fans of certain celebrities or cultural phenomena, particularly Lady Gaga (known as Monsters), Justin Bieber (Beliebers) and fans of the Twilight (Twihards) and Harry Potter (Potterheads) novels. Twitter have altered the trend algorithm in the past to prevent manipulation of this type.[87]

Twitter's March 30, 2010 blog post announced that the hottest Twitter trending topics would scroll across the Twitter homepage.[88]

There have been controversies surrounding Twitter trending topics: Twitter has censored hashtags that other users found offensive. Twitter censored the #Thatsafrican[89] and the #thingsdarkiessay[90] hashtags after users complained that they found the hashtags offensive.[citation needed]
Adding and following content

There are numerous tools for adding content, monitoring content and conversations including Twitvid (video sharing),[91] TweetDeck, Salesforce.com, HootSuite, and Twitterfeed. As of 2009, fewer than half of tweets were posted using the web user interface with most users using third-party applications (based on analysis of 500 million tweets by Sysomos).[92]
Verified accounts

In June 2008, Twitter launched a verification program, allowing celebrities to get their accounts verified.[93] Originally intended to help users verify which celebrity accounts were created by the celebrities themselves (and therefore are not fake), they have since been used to verify accounts of businesses and accounts for public figures who may not actually tweet but still wish to maintain control over the account that bears their name - for example, the Dalai Lama.
Mobile
The mobile version of Twitter, mobile.twitter.com

Twitter has mobile apps for iPhone, iPad, Android, Windows Phone, BlackBerry, and Nokia S40.[94] There is also version of the website for mobile devices as well as SMS and MMS service.[95] Twitter limits the use of 3rd party applications utilizing the service by implementing a 100,000 user limit.[96]
Authentication

As of August 31, 2010, third-party Twitter applications are required to use OAuth, an authentication method that does not require users to enter their password into the authenticating application. Previously, the OAuth authentication method was optional, it is now compulsory and the user-name/password authentication method has been made redundant and is no longer functional. Twitter stated that the move to OAuth will mean "increased security and a better experience".[97]
Usage
Rankings

Twitter is ranked as one of the ten-most-visited websites worldwide by Alexa's web traffic analysis.[98] Daily user estimates vary as the company does not publish statistics on active accounts. A February 2009 Compete.com blog entry ranked Twitter as the third most used social network based on their count of 6 million unique monthly visitors and 55 million monthly visits.[99] In March 2009, a Nielsen.com blog ranked Twitter as the fastest-growing website in the Member Communities category for February 2009. Twitter had annual growth of 1,382 percent, increasing from 475,000 unique visitors in February 2008 to 7 million in February 2009.[100] In 2009, Twitter had a monthly user retention rate of forty percent.[101]
Demographics
Twitter.com Top5 Global Markets by Reach (%)[102][103]
Country             Percent    
Indonesia     Jun 2010    
  
    20.8%    
Dec 2010    
  
    19.0%
Brazil     Jun 2010    
  
    20.5%    
Dec 2010    
  
    21.8%
Venezuela     Jun 2010    
  
    19.0%    
Dec 2010    
  
    21.1%
Netherlands     Jun 2010    
  
    17.7%    
Dec 2010    
  
    22.3%
Japan     Jun 2010    
  
    16.8%    
Dec 2010    
  
    20.0%
Note: Visitor age 15+, home and work locations. Excludes visitation from public computers such as Internet cafes or access from mobile phones or PDAs.

In 2009, Twitter was mainly used by older adults who might not have used other social sites before Twitter, said Jeremiah Owyang, an industry analyst studying social media. "Adults are just catching up to what teens have been doing for years," he said.[104] According to comScore only eleven percent of Twitter's users are aged twelve to seventeen.[104] comScore attributed this to Twitter's "early adopter period" when the social network first gained popularity in business settings and news outlets attracting primarily older users. However, comScore also stated in 2009 that Twitter had begun to "filter more into the mainstream", and "along with it came a culture of celebrity as Shaq, Britney Spears and Ashton Kutcher joined the ranks of the Twitterati."[105]

According to a study by Sysomos in June 2009, women make up a slightly larger Twitter demographic than men — fifty-three percent over forty-seven percent. It also stated that five percent of users accounted for seventy-five percent of all activity, and that New York City has more Twitter users than other cities.[106]

According to Quancast, twenty-seven million people in the US used Twitter as of September 3, 2009. Sixty-three percent of Twitter users are under thirty-five years old; sixty percent of Twitter users are Caucasian, but a higher than average (compared to other Internet properties) are African American/black (sixteen percent) and Hispanic (eleven percent); fifty-eight percent of Twitter users have a total household income of at least US$60,000.[107] The prevalence of African American Twitter usage and in many popular hashtags has been the subject of research studies.[108][109]

On September 7, 2011, Twitter announced that it has 100 million active users logging in at least once a month and 50 million active users every day.[110]

In an article published on January 6, 2012, Twitter was confirmed to be the biggest social media network in Japan, with Facebook following closely in second. comScore confirmed this, stating that Japan is the only country in the world where Twitter leads Facebook.[111]
Finances
Funding
Twitter's San Francisco headquarters located at 1355 Market St.

Twitter raised over US$57 million from venture capitalist growth funding, although exact numbers are not publicly disclosed. Twitter's first A round of funding was for an undisclosed amount that is rumored to have been between US$1 million and US$5 million.[112] Its second B round of funding in 2008 was for US$22 million[113] and its third C round of funding in 2009 was for US$35 million from Institutional Venture Partners and Benchmark Capital along with an undisclosed amount from other investors including Union Square Ventures, Spark Capital and Insight Venture Partners.[112] Twitter is backed by Union Square Ventures, Digital Garage, Spark Capital, and Bezos Expeditions.[114]

In May 2008, The Industry Standard remarked that Twitter's long-term viability is limited by a lack of revenue.[115] Twitter board member Todd Chaffee forecast that the company could profit from e-commerce, noting that users may want to buy items directly from Twitter since it already provides product recommendations and promotions.[116]

The company raised US$200 million in new venture capital in December 2010, at a valuation of approximately US$3.7 billion.[117] In March 2011, 35,000 Twitter shares sold for US$34.50 each on Sharespost, an implied valuation of US$7.8 billion.[118] In August, 2010 Twitter announced a "significant" investment lead by Digital Sky Technologies that, at US$800 million, was reported to be the largest venture round in history.[119]

Twitter has been identified as a possible candidate for an initial public offering by 2013.[120]

In December 2011, the Saudi prince Alwaleed bin Talal invested $300 million in Twitter. The company was valued at $8.4 billion at the time.[121]
Revenue sources

In July 2009, some of Twitter's revenue and user growth documents were published on TechCrunch after being illegally obtained by Hacker Croll. The documents projected 2009 revenues of US$400,000 in the third quarter and US$4 million in the fourth quarter along with 25 million users by the end of the year. The projections for the end of 2013 were US$1.54 billion in revenue, US$111 million in net earnings, and 1 billion users.[3] No information about how Twitter planned to achieve those numbers was published. In response, Twitter co-founder Biz Stone published a blog post suggesting the possibility of legal action against the hacker.[122]

On April 13, 2010, Twitter announced plans to offer paid advertising for companies that would be able to purchase "promoted tweets" to appear in selective search results on the Twitter website, similar to Google Adwords' advertising model. As of April 13, Twitter announced it had already signed up a number of companies wishing to advertise including Sony Pictures, Red Bull, Best Buy, and Starbucks.[123][124]

To continue their advertising campaign, Twitter announced on March 20, 2012, that it would be bringing its promoted tweets to mobile devices. Twitter generated US$139.5 million in advertising sales during 2011 and expects this number to grow 86.3% to US$259.9 million in 2012.[125]

The company generated US$45 million in annual revenue in 2010, after beginning sales midway through that year. The company operated at a loss through most of 2010. Revenues were forecast for US$100 million to US$110 million in 2011.[117] Users' photos can generate royalty-free revenue for Twitter, with an agreement with WENN being announced in May 2011.[126] In June 2011, Twitter announced that it would offer small businesses a self serve advertising system.[127]
Technology
Implementation

Great reliance is placed on open-source software.[128] The Twitter Web interface uses the Ruby on Rails framework,[129] deployed on a performance enhanced Ruby Enterprise Edition implementation of Ruby.[130]

As of April 6, 2011, Twitter engineers confirmed they had switched away from their Ruby on Rails search-stack, to a Java server they call Blender.[6]

From spring 2007 to 2008 the messages were handled by a Ruby persistent queue server called Starling,[131] but since 2009 implementation has been gradually replaced with software written in Scala.[132] The service's application programming interface (API) allows other web services and applications to integrate with Twitter.[133][134]

Individual tweets are registered under unique IDs using software called snowflake and geolocation data is added using 'Rockdove'. The URL shortner t.co then checks for a spam link and shortens the URL. The tweets are stored in a MySQL database using Gizzard and acknowledged to users as having been sent. They are then sent to search engines via the Firehose API. The process itself is managed by FlockDB and takes an average of 350 ms.[128]
Interface

On April 30, 2009, Twitter adjusted its web interface, adding a search bar and a sidebar of "trending topics" — the most common phrases appearing in messages. Biz Stone explains that all messages are instantly indexed and that "with this newly launched feature, Twitter has become something unexpectedly important – a discovery engine for finding out what is happening right now."[135]

In March 2012, Twitter became available in Arabic, Farsi, Hebrew and Urdu, the first right-to-left language versions of the site. About 13,000 volunteers helped with translating the menu options.[136] In August 2012, beta support for Basque, Czech and Greek was added, making the site available in 33 different languages.[137]
Outages
The Twitter fail whale error message.

When Twitter experiences an outage, users see the "fail whale" error message image created by Yiying Lu,[138] illustrating eight orange birds using a net to hoist a whale from the ocean captioned "Too many tweets! Please wait a moment and try again."[139]

Twitter had approximately ninety-eight percent uptime in 2007 (or about six full days of downtime).[140] The downtime was particularly noticeable during events popular with the technology industry such as the 2008 Macworld Conference & Expo keynote address.[141][142]

    May 2008 – Twitter's new engineering team made architectural changes to deal with the scale of growth. Stability issues resulted in down time or temporary feature removal.
    August 2008 – Twitter withdrew free SMS services from users in the United Kingdom[143] and for approximately five months instant messaging support via a XMPP bot was listed as being "temporarily unavailable".[144]
    October 10, 2008 – Twitter's status blog announced that instant messaging (IM) service was no longer a temporary outage and needed to be revamped. It was announced that Twitter aims to return its IM service pending necessary major work.[145]
    June 12, 2009 – In what was called a potential "Twitpocalypse", the unique numerical identifier associated with each tweet exceeded the limit of 32-bit signed integers (2,147,483,647 total messages).[146] While Twitter itself was not affected, some third-party clients could no longer access recent tweets. Patches were quickly released, though some iPhone applications had to wait for approval from the App Store.[147]
    June 25, 2009 – Twitter ran slowly for some time after over 50,000 tweets on Michael Jackson’s death were recorded in an hour.[148]
    August 6, 2009 – Twitter and Facebook suffered from a denial-of-service attack, causing the Twitter website to go offline for several hours.[149] It was later confirmed that the attacks were directed at one pro-Georgian user around the anniversary of the 2008 South Ossetia War, rather than the sites themselves.[150]
    September 22, 2009 – The identifier exceeded the limit for 32-bit unsigned integers (4,294,967,296 total messages) again breaking some third-party clients.[151]
    December 17, 2009 – A hacking attack replaced the website's welcoming screen with an image of a green flag and the caption "This site has been hacked by Iranian Cyber Army" for nearly an hour. No connection between the hackers and Iran has been established.[152]
    June–July 2010 – Twitter had a very high service rejection rate (10–20%) during the 2010 FIFA World Cup period, also, the response latency increased substantially.[153]
    November 2010 – A number of accounts encountered a fault that resulted in them seeing the "fail whale" when they tried to login to their accounts. The accounts themselves were not locked out as account holders could still see their "mentions" page, and post from there, but the timeline and a number of other features were unavailable during this outage.
    June 21, 2012 – The site was down for around one hour and forty minutes, with the cause being described by Twitter as a "cascading bug".[154]
    July 26, 2012 – Twitter users in the UK could not post messages for part of the day in advance of the 2012 Summer Olympics.[155]

Privacy and security

Twitter messages are public but users can also send private messages.[156] Twitter collects personally identifiable information about its users and shares it with third parties. The service reserves the right to sell this information as an asset if the company changes hands.[157] While Twitter displays no advertising, advertisers can target users based on their history of tweets and may quote tweets in ads[158] directed specifically to the user.

A security vulnerability was reported on April 7, 2007, by Nitesh Dhanjani and Rujith. Since Twitter used the phone number of the sender of an SMS message as authentication, malicious users could update someone else's status page by using SMS spoofing.[159] The vulnerability could be used if the spoofer knew the phone number registered to their victim's account. Within a few weeks of this discovery Twitter introduced an optional personal identification number (PIN) that its users could use to authenticate their SMS-originating messages.[160]

On January 5, 2009, 33 high-profile Twitter accounts were compromised after a Twitter administrator's password was guessed by a dictionary attack.[161] Falsified tweets — including sexually explicit and drug-related messages — were sent from these accounts.[162]

Twitter launched the beta version of their "Verified Accounts" service on June 11, 2009, allowing famous or notable people to announce their Twitter account name. The home pages of these accounts display a badge indicating their status.[163]

In May 2010, a bug was discovered by İnci Sözlük, involving users that allowed Twitter users to force others to follow them without the other users' consent or knowledge. For example, comedian Conan O'Brien's account, which had been set to follow only one person, was changed to receive nearly 200 malicious subscriptions.[164]

In response to Twitter's security breaches, the US Federal Trade Commission brought charges against the service which were settled on June 24, 2010. This was the first time the FTC had taken action against a social network for security lapses. The settlement requires Twitter to take a number of steps to secure users' private information, including maintenance of a "comprehensive information security program" to be independently audited biannually.[165]

On December 14, 2010, the United States Department of Justice issued a subpoena directing Twitter to provide information for accounts registered to or associated with WikiLeaks.[166] Twitter decided to notify its users and said in a statement, "...it's our policy to notify users about law enforcement and governmental requests for their information, unless we are prevented by law from doing so".[156]

A "MouseOver" exploit occurred on September 21, 2010, when an XSS Worm became active on Twitter. When an account user held the mouse cursor over blacked-out parts of a tweet, the worm within the script would automatically open links and re-post itself on the reader's account.[167] The exploit was then re-used to post pop-up ads and links to pornographic sites. The origin is unclear but Pearce H. Delphin (known on Twitter as @zzap) and a Scandinavian developer, Magnus Holm, both claim to have modified the exploit of a user, possibly Masato Kinugawa, who was using it to create coloured Tweets.[168] Kinugawa, a Japanese developer, reported the XSS vulnerability to Twitter on August 14. Later, when he found it was exploitable again, he created the account 'RainbowTwtr' and used it to post coloured messages.[168] Delphin says he exposed the security flaw by tweeting a JavaScript function for "onMouseOver",[168] and Holm later created and posted the XSS Worm that automatically re-tweeted itself.[167] Security firm Sophos reported that the virus was spread by people doing it for "fun and games", but noted it could be exploited by cybercriminals.[167] Twitter issued a statement on their status blog at 13:50 UTC that "The exploit is fully patched". Twitter representative Carolyn Penner said no charges would be pressed.[170]

In May 2011, a claimant known as "CTB" (subsequently identified as Ryan Giggs) in the case of CTB v Twitter Inc., Persons Unknown took legal action at the High Court of Justice in London against Twitter.,[171] requesting that Twitter release details of account holders. This followed gossip posted on Twitter about Giggs' private life, causing conflict relating to privacy injunctions.[172][173] Tony Wang, the head of Twitter in Europe, said that people who do "bad things" on the site would need to defend themselves under the laws of their own jurisdiction in the event of controversy, and that the site would hand over information about users to the authorities when it was legally required to do so.[174] He also suggested that Twitter would accede to a UK court order to divulge names of users responsible for "illegal activity" on the site.[175]

On May 29, 2011, it was reported that South Tyneside council in England had successfully taken legal action against Twitter in a court in California, which forced Twitter to reveal the details of five user accounts. The council was trying to discover the identity of a blogger called "Mr Monkey"[176] who allegedly posted libellous statements about three local councillors.[177]

On January 23, 2012, it was reported that Twitter would be acquiring Dasient, a startup that offers malware protection for businesses. Twitter hopes that Dasient will help remove hateful advertisers on the website.[178]

On January 26, 2012, Twitter began offering a feature which would allow tweets to be removed selectively by country. Twitter cited France and Germany as examples, where pro-Nazi content is illegal. Previously, deleted tweets were removed in all countries.[179][180] The first use of the policy was to block the account of German neo-Nazi group Besseres Hannover on October 18, 2012.[181] The policy was used again the following day to remove anti-Semitic French tweets with the hashtag #unbonjuif ("a good jew").[182]

On February 20, 2012, a third-party public-key encryption app (written in Python and partially funded by a grant from the Shuttleworth Foundation[183]) for private messaging in Twitter, CrypTweet, was released.[184]

On May 17, 2012, Twitter announced it would implement the "Do Not Track" privacy option, a cookie-blocking feature found in Mozilla's Firefox browser. The "Do Not Track" feature works only on sites that have agreed to the service.[185]

In August 2012 it was reported that there is a market in fake Twitter followers that are used to increase politicians' and celebrities' apparent popularity.[186]
Open source

Twitter released several open source projects developed while overcoming technical challenges of their service.[187] Notable projects are the Gizzard Scala framework for creating distributed datastores and the distributed graph database FlockDB.
Innovators patent agreement

On April 17, 2012, Twitter announced it would implement an “Innovators Patent Agreement” which would obligate Twitter to only use its patents for defensive purposes. The agreement will go into effect later 2012.[188]

URL shortener

t.co is a URL shortening service created by Twitter.[84] It is only available for links posted to Twitter and not available for general use.[84] All links posted to Twitter use a t.co wrapper.[189] Twitter hopes that the service will be able to protect users from malicious sites,[84] and will use it to track clicks on links within tweets.[84][190]

Having previously used the services of third parties TinyURL and bit.ly,[191] Twitter began experimenting with its own URL shortening service for private messages in March 2010 using the twt.tl domain,[189] before it purchased the t.co domain. The service was tested on the main site using the accounts @TwitterAPI, @rsarver and @raffi.[189] On September 2, 2010, an email from Twitter to users said they would be expanding the roll-out of the service to users. On June 7, 2011, Twitter announced that it was rolling out the feature.[192]
Integrated photo-sharing service

On June 1, 2011, Twitter announced its own integrated photo-sharing service that enables users to upload a photo and attach it to a Tweet right from Twitter.com.[193] Users now also have the ability to add pictures to Twitter's search by adding hashtags to the tweet.[194] Twitter also plans to provide photo galleries designed to gather and syndicate all photos that a user has uploaded on Twitter and third-party services such as TwitPic.

Europe

Europe (Listeni/ˈjʊərəp/ EWR-əp or /ˈjɜrəp/ YUR-əp[1]) is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally divided from Asia by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting the Black and Aegean Seas.[2]

Europe is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and the Black Sea and connected waterways to the southeast. Yet the borders of Europe—a concept dating back to classical antiquity—are somewhat arbitrary, as the primarily physiographic term "continent" can incorporate cultural and political elements.

Europe is the world's second-smallest continent by surface area, covering about 10,180,000 square kilometres (3,930,000 sq mi) or 2% of the Earth's surface and about 6.8% of its land area. Of Europe's approximately 50 states, Russia is by far the largest by both area and population, taking up 40% of the continent (although the country has territory in both Europe and Asia), while Vatican City is the smallest. Europe is the third-most populous continent after Asia and Africa, with a population of 733 million or about 11% of the world's population.[3]

Europe, in particular Ancient Greece, is the birthplace of Western culture.[4] It played a predominant role in global affairs from the 15th century onwards, especially after the beginning of colonialism. Between the 16th and 20th centuries, European nations controlled at various times the Americas, most of Africa, Oceania, and large portions of Asia. In 1900, Europe's share of the world's population was 25%.[5]

Both World Wars were largely focused upon Europe, greatly contributing to a decline in Western European dominance in world affairs by the mid-20th century as the United States and Soviet Union took prominence.[6] During the Cold War, Europe was divided along the Iron Curtain between NATO in the west and the Warsaw Pact in the east. European integration led to the formation of the Council of Europe and the European Union in Western Europe, both of which have been expanding eastward since the revolutions of 1989 and the fall of the Soviet Union in 1991.
 Definition
Further information: List of countries spanning more than one continent
Further information: Borders of the continents
Reconstruction of Herodotus' world map
A medieval T and O map from 1472 showing the division of the world into 3 continents
Europa regina map from Münster (1570). The British Isles and Scandinavia are not included in Europe proper.

The use of the term "Europe" has developed gradually throughout history.[7][8] In antiquity, the Greek historian Herodotus mentioned that the world had been divided by unknown persons into three parts, Europe, Asia, and Libya (Africa), with the Nile and the River Phasis forming their boundaries—though he also states that some considered the River Don, rather than the Phasis, as the boundary between Europe and Asia.[9] Europe's eastern frontier was defined in the 1st century by geographer Strabo at the River Don.[10] Flavius and the Book of Jubilees described the continents as the lands given by Noah to his three sons; Europe was defined as stretching from the Pillars of Hercules at the Strait of Gibraltar, separating it from North Africa, to the Don, separating it from Asia.[11]

A cultural definition of Europe as the lands of Latin Christendom coalesced in the 8th century, signifying the new cultural condominium created through the confluence of Germanic traditions and Christian-Latin culture, defined partly in contrast with Byzantium and Islam, and limited to northern Iberia, the British Isles, France, Christianized western Germany, the Alpine regions and northern and central Italy.[12] The concept is one of the lasting legacies of the Carolingian Renaissance: "Europa" often figures in the letters of Charlemagne's cultural minister, Alcuin.[13] This division—as much cultural as geographical—was used until the Late Middle Ages, when it was challenged by the Age of Discovery.[14][15][why?] The problem of redefining Europe was finally resolved in 1730 when, instead of waterways, the Swedish geographer and cartographer von Strahlenberg proposed the Ural Mountains as the most significant eastern boundary, a suggestion that found favour in Russia and throughout Europe.[16]

Europe is now generally defined by geographers as the westernmost peninsula of Eurasia, with its boundaries marked by large bodies of water to the north, west and south; Europe's limits to the far east are usually taken to be the Urals, the Ural River, and the Caspian Sea; to the south-east, including the Caucasus Mountains, the Black Sea and the waterways connecting the Black Sea to the Mediterranean Sea.[17] Because of sociopolitical and cultural differences, there are various descriptions of Europe's boundary. For example, Cyprus is approximate to Anatolia (or Asia Minor), but is usually considered part of Europe and currently is a member state of the EU. In addition, Malta was considered an island of North Africa for centuries,[18] while Iceland, though nearer to Greenland (North America), is also generally included in Europe.

Sometimes, the word 'Europe' is used in a geopolitically limiting way[19] to refer only to the European Union or, even more exclusively, a culturally defined core. On the other hand, the Council of Europe has 47 member countries, and only 27 member states are in the EU.[20] In addition, people living in areas such as Ireland, the United Kingdom, the North Atlantic and Mediterranean islands and also in Scandinavia may routinely refer to "continental" or "mainland" Europe simply as Europe or "the Continent".[21]

Clickable map of Europe, showing one of the most commonly used continental boundaries[22]
Key: blue: states which straddle the border between Europe and Asia; green: states not geographically in Europe, but closely associated politically[23]
Alb.
And.
Austria
Armenia
Azer.
Belarus
Belgium
BiH
Bulgaria
Croatia
Cyprus
Czech
Rep.
Denmark
Estonia
Finland
France
Germany
Georgia
Greece
Greenland (Dk)
Hungary
Iceland
Ireland
Italy
S. Mar.
Kazakhstan
Kos.
Latvia
Liech.
Lithuania
Lux.
Mac.
Malta
Moldova
Mon.
Mont.
Neth.
Norway
Svalbard (Nor)
Poland
Portugal
Romania
Russia
Serbia
Slovakia
Slo.
Spain
Sweden
Switz-
erland
Turkey
Ukraine
United
Kingdom
Far. (Dk)
Vat.


Adr-
iatic
Sea
Arctic Ocean
Baltic
Sea
Aegean
Sea
Barents Sea
Bay of
Biscay
Black
Sea
Azov
Sea
Caspian
Sea
Celtic
Sea
Greenland Sea
Baffin Bay
Gulf of
Cadiz
Ligurian
Sea
Mediterranean Sea
North
Atlantic
Ocean
North
Sea
Norwegian
Sea
Strait of Gibraltar
Etymology
Europa and the bull on a Greek vase. Tarquinia Museum, circa 480 BC

In ancient Greek mythology, Europa was a Phoenician princess whom Zeus abducted after assuming the form of a dazzling white bull. He took her to the island of Crete where she gave birth to Minos, Rhadamanthus, and Sarpedon. For Homer, Europe (Ancient Greek: Εὐρώπη, Eurṓpē; see also List of Greek place names) was a mythological queen of Crete, not a geographical designation.

The etymology of Europa is uncertain.[24] One theory suggests that it is derived from the Greek εὐρύς (eurus), meaning "wide, broad"[25] and ὤψ/ὠπ-/ὀπτ- (ōps/ōp-/opt-), meaning "eye, face, countenance",[26] hence Eurṓpē, "wide-gazing", "broad of aspect" (compare with glaukōpis (γλαυκῶπις 'grey-eyed') Athena or boōpis (βοὠπις 'ox-eyed') Hera). Broad has been an epithet of Earth itself in the reconstructed Proto-Indo-European religion.[27] Another theory suggests that it is based on a Semitic word such as the Akkadian erebu meaning "to go down, set" (cf. Occident),[28] cognate to Phoenician 'ereb "evening; west" and Arabic Maghreb, Hebrew ma'ariv (see also Erebus, PIE *h1regʷos, "darkness"). However, Martin Litchfield West states that "phonologically, the match between Europa's name and any form of the Semitic word is very poor".[29]

Whatever the origin of the name of the mythological figure, Εὐρώπη is first used as a geographical term in the 6th century BC, by Greek geographers such as Anaximander and Hecataeus. Anaximander placed the boundary between Asia and Europe along the Phasis River (the modern Rioni) in the Caucasus, a convention still followed by Herodotus in the 5th century BC.[30] But the convention received by the Middle Ages and surviving into modern usage is that of the Roman era used by Roman era authors such as Posidonius,[31] Strabo[32] and Ptolemy,[33] who took the Tanais (the modern Don River) as the boundary. The term "Europe" is first used for a cultural sphere in the Carolingian Renaissance of the 9th century. From that time, the term designated the sphere of influence of the Western Church, as opposed to both the Eastern Orthodox churches and to the Islamic world. The modern convention, enlarging the area of "Europe" somewhat to the east and the south-east, develops in the 19th century.

Most major world languages use words derived from "Europa" to refer to the "continent" (peninsula). Chinese, for example, uses the word Ōuzhōu (歐洲); this term is also used by the European Union in Japanese-language diplomatic relations, despite the katakana Yōroppa (ヨーロッパ?) being more commonly used. However, in some Turkic languages the originally Persian name Frangistan (land of the Franks) is used casually in referring to much of Europe, besides official names such as Avrupa or Evropa.[34]
History
Main article: History of Europe
Prehistory
Main article: Prehistoric Europe
Ġgantija, Malta
The Lady of Vinča, neolithic pottery from Serbia
Stonehenge, England
The Nebra sky disk from Bronze age Germany

Homo georgicus, which lived roughly 1.8 million years ago in Georgia, is the earliest hominid to have been discovered in Europe.[35] Other hominid remains, dating back roughly 1 million years, have been discovered in Atapuerca, Spain.[36] Neanderthal man (named for the Neandertal valley in Germany) appeared in Europe 150,000 years ago and disappeared from the fossil record about 28,000 BC, with this extinction probably due to climate change, and their final refuge being present-day Portugal. The Neanderthals were supplanted by modern humans (Cro-Magnons), who appeared in Europe around 43 to 40 thousand years ago.[37]

The European Neolithic period—marked by the cultivation of crops and the raising of livestock, increased numbers of settlements and the widespread use of pottery—began around 7000 BC in Greece and the Balkans, probably influenced by earlier farming practices in Anatolia and the Near East. It spread from the Balkans along the valleys of the Danube and the Rhine (Linear Pottery culture) and along the Mediterranean coast (Cardial culture). Between 4500 and 3000 BC, these central European neolithic cultures developed further to the west and the north, transmitting newly acquired skills in producing copper artefacts. In Western Europe the Neolithic period was characterized not by large agricultural settlements but by field monuments, such as causewayed enclosures, burial mounds and megalithic tombs.[38] The Corded Ware cultural horizon flourished at the transition from the Neolithic to the Chalcolithic. During this period giant megalithic monuments, such as the Megalithic Temples of Malta and Stonehenge, were constructed throughout Western and Southern Europe.[39][40] The European Bronze Age began circa 3200 BC in Greece.[41]

The European Iron Age began around 1200 BC.[42] Iron Age colonisation by the Greeks and Phoenicians gave rise to early Mediterranean cities. Early Iron Age Italy and Greece from around the 8th century BC gradually gave rise to historical Classical antiquity.
Classical antiquity
Main article: Classical antiquity
See also: Ancient Greece and Ancient Rome
The Greek Temple of Apollo, Paestum, Italy

Ancient Greece had a profound influence on Western civilisation. Western democratic and individualistic culture are often attributed to Ancient Greece.[43] The Greeks invented the polis, or city-state, which played a fundamental role in their concept of identity.[44] These Greek political ideals were rediscovered in the late 18th century by European philosophers and idealists. Greece also generated many cultural contributions: in philosophy, humanism and rationalism under Aristotle, Socrates and Plato; in history with Herodotus and Thucydides; in dramatic and narrative verse, starting with the epic poems of Homer;[43] in medicine with Hippocrates and Galen; and in science with Pythagoras, Euclid and Archimedes.[45][46][47]
The Roman Empire at its greatest extent

Another major influence came on Europe that would impact Western civilisation from the Roman Empire which left its mark on law, politics, language, engineering, architecture, government and many more aspects in western civilization.[48] During the pax romana, the Roman Empire expanded to encompass the entire Mediterranean Basin and much of Europe.[49]

Stoicism influenced Roman emperors such as Hadrian, Antoninus Pius, and Marcus Aurelius, who all spent time on the Empire's northern border fighting Germanic, Pictish and Scottish tribes.[50][51] Christianity was eventually legitimised by Constantine I after three centuries of imperial persecution.
Early Middle Ages
Main articles: Late Antiquity and Early Middle Ages
See also: Dark Ages (historiography) and Age of Migrations
Roland pledges fealty to Charlemagne, Holy Roman Emperor.

During the decline of the Roman Empire, Europe entered a long period of change arising from what historians call the "Age of Migrations". There were numerous invasions and migrations amongst the Ostrogoths, Visigoths, Goths, Vandals, Huns, Franks, Angles, Saxons, Slavs, Avars, Bulgars and, later still, the Vikings and Magyars.[49] Renaissance thinkers such as Petrarch would later refer to this as the "Dark Ages".[52] Isolated monastic communities were the only places to safeguard and compile written knowledge accumulated previously; apart from this very few written records survive and much literature, philosophy, mathematics, and other thinking from the classical period disappeared from Europe.[53]
Europe around 650

From the 7th century Byzantine history was greatly affected by the rise of Islam and the Caliphates. Muslim Arabs first invaded historically Roman territory under Abū Bakr, first Caliph of the Rashidun Caliphate, who entered Roman Syria and Roman Mesopotamia. Under Umar, the second Caliph, the Muslims decisively conquered Syria and Mesopotamia, as well as Roman Palestine, Roman Egypt, and parts of Asia Minor and Roman North Africa. This trend continued under Umar's successors and under the Umayyad Caliphate, which conquered the rest of Mediterranean North Africa and most of the Iberian Peninsula. Over the next centuries Muslim forces were able to take further European territory, including Cyprus, Malta, Crete, and Sicily and parts of southern Italy.[54] In the East, Volga Bulgaria became an Islamic state in the tenth century.[55]

The Muslim conquest of Hispania began when the Moors (mostly Berbers with some Arabs) invaded the Christian Visigothic kingdom of Iberia in the year 711, under their Berber leader Tariq ibn Ziyad. They landed at Gibraltar on 30 April and worked their way northward. Tariq's forces were joined the next year by those of his superior, Musa ibn Nusair. During the eight-year campaign most of the Iberian Peninsula was brought under Muslim rule — save for small areas in the northwest (Asturias) and largely Basque regions in the Pyrenees. This territory, under the Arab name Al-Andalus, became part of the expanding Umayyad empire.

The unsuccessful second siege of Constantinople (717) weakened the Umayyad dynasty and reduced their prestige. After their success in overrunning Iberia, the conquerors moved northeast across the Pyrenees, but were defeated by the Frankish leader Charles Martel at the Battle of Poitiers in 732. The Umayyads were overthrown in 750 by the 'Abbāsids and most of the Umayyad clan massacred.

A surviving Umayyad prince, Abd-ar-rahman I, escaped to Spain and founded a new Umayyad dynasty in the Emirate of Cordoba, (756). Charles Martel's son, Pippin the Short retook Narbonne, and his grandson Charlemagne established the Marca Hispanica across the Pyrenees in part of what today is Catalonia, reconquering Girona in 785 and Barcelona in 801. The Umayyads in Spain proclaimed themselves caliphs in 929.

During the Dark Ages, the Western Roman Empire fell under the control of various tribes. The Germanic and Slav tribes established their domains over Western and Eastern Europe respectively.[56] Eventually the Frankish tribes were united under Clovis I.[57] Charlemagne, a Frankish king of the Carolingian dynasty who had conquered most of Western Europe, was anointed "Holy Roman Emperor" by the Pope in 800. This led to the founding of the Holy Roman Empire, which eventually became centred in the German principalities of central Europe.[58]

The predominantly Greek speaking Eastern Roman Empire became known in the West as the Byzantine Empire. Its capital was Constantinople. Emperor Justinian I presided over Constantinople's first golden age: he established a legal code, funded the construction of the Hagia Sophia and brought the Christian church under state control.[59] Fatally weakened by the sack of Constantinople in 1204, during the Fourth Crusade, Byzantium fell in 1453 when it was conquered by the Ottoman Empire. Middle Ages
Main articles: High Middle Ages, Late Middle Ages, and Middle Ages
See also: Medieval demography

The economic growth of Europe around the year 1000, together with the lack of safety on the mainland trading routes, made possible the development of major commercial routes along the coast of the Mediterranean Sea. In this context, the growing independence acquired by some coastal cities gave the Maritime Republics a leading role in the European scene.
Tancred of Sicily and Philip II of France, during the Third Crusade

The Middle Ages on the mainland were dominated by the two upper echelons of the social structure: the nobility and the clergy. Feudalism developed in France in the Early Middle Ages and soon spread throughout Europe.[72] A struggle for influence between the nobility and the monarchy in England led to the writing of the Magna Carta and the establishment of a parliament.[73] The primary source of culture in this period came from the Roman Catholic Church. Through monasteries and cathedral schools, the Church was responsible for education in much of Europe.[72]

The Papacy reached the height of its power during the High Middle Ages. An East-West Schism in 1054 split the former Roman Empire religiously, with the Eastern Orthodox Church in the Byzantine Empire and the Roman Catholic Church in the former Western Roman Empire. In 1095 Pope Urban II called for a crusade against Muslims occupying Jerusalem and the Holy Land.[74] In Europe itself, the Church organised the Inquisition against heretics. In Spain, the Reconquista concluded with the fall of Granada in 1492, ending over seven centuries of Islamic rule in the Iberian Peninsula.[75]
The sacking of Suzdal by Batu Khan in 1238, during the Mongol invasion of Europe.

In the 11th and 12th centuries, constant incursions by nomadic Turkic tribes, such as the Pechenegs and the Cuman-Kipchaks, caused a massive migration of Slavic populations to the safer, heavily forested regions of the north and temporarily halted the expansion of the Rus' state to the south and east.[76] Like many other parts of Eurasia, these territories were overrun by the Mongols.[77] The invaders, who became known as Tatars, were mostly Turkic under Mongol command. They established the state of the Golden Horde, which later adopted Islam as a religion and ruled over modern-day southern and central Russia for more than three centuries.[78][79]

The Great Famine of 1315–1317 was the first crisis that would strike Europe in the late Middle Ages.[80] The period between 1348 and 1420 witnessed the heaviest loss. The population of France was reduced by half.[81][82] Medieval Britain was afflicted by 95 famines,[83] and France suffered the effects of 75 or more in the same period.[84] Europe was devastated in the mid-14th century by the Black Death, one of the most deadly pandemics in human history which killed an estimated 25 million people in Europe alone—a third of the European population at the time.[85]

The plague had a devastating effect on Europe's social structure; it induced people to live for the moment as illustrated by Giovanni Boccaccio in The Decameron (1353). It was a serious blow to the Roman Catholic Church and led to increased persecution of Jews, foreigners, beggars and lepers.[86] The plague is thought to have returned every generation with varying virulence and mortalities until the 18th century.[87] During this period, more than 100 plague epidemics swept across Europe.[88]
Early modern period
Main article: Early modern period
See also: Renaissance, Protestant Reformation, Scientific Revolution, and Age of Discovery
The School of Athens by Raphael: Contemporaries such as Michelangelo and Leonardo da Vinci (centre) are portrayed as classical scholars
Battle of Vienna in 1683 broke the advance of the Ottoman Empire into Europe

The Renaissance was a period of cultural change originating in Florence and later spreading to the rest of Europe. in the 14th century. The rise of a new humanism was accompanied by the recovery of forgotten classical Greek and Arabic knowledge from monastic libraries, often re-translated from Arabic into Latin.[89][90][91] The Renaissance spread across Europe between the 14th and 16th centuries: it saw the flowering of art, philosophy, music, and the sciences, under the joint patronage of royalty, the nobility, the Roman Catholic Church, and an emerging merchant class.[92][93][94] Patrons in Italy, including the Medici family of Florentine bankers and the Popes in Rome, funded prolific quattrocento and cinquecento artists such as Raphael, Michelangelo, and Leonardo da Vinci.[95][96]

Political intrigue within the Church in the mid-14th century caused the Great Schism. During this forty-year period, two popes—one in Avignon and one in Rome—claimed rulership over the Church. Although the schism was eventually healed in 1417, the papacy's spiritual authority had suffered greatly.[97]

The Church's power was further weakened by the Protestant Reformation (1517–1648), initially sparked by the works of German theologian Martin Luther, a result of the lack of reform within the Church. The Reformation also damaged the Holy Roman Empire's power, as German princes became divided between Protestant and Roman Catholic faiths.[98] This eventually led to the Thirty Years War (1618–1648), which crippled the Holy Roman Empire and devastated much of Germany, killing between 25 and 40 percent of its population.[99] In the aftermath of the Peace of Westphalia, France rose to predominance within Europe.[100] The 17th century in southern and eastern Europe was a period of general decline.[101] Eastern Europe experienced more than 150 famines in a 200-year period between 1501 to 1700.[102] In the 15th–18th centuries, when the disintegrating khanates of the Golden Horde were conquered by Russia, Tatars from the Crimean Khanate frequently raided Eastern Slavic lands to capture slaves.[103]

The Renaissance and the New Monarchs marked the start of an Age of Discovery, a period of exploration, invention, and scientific development.[104] Among the great figures of the Western scientific revolution of the 16th and 17th centuries were Copernicus, Kepler, Galileo, and Isaac Newton.[105] According to Peter Barrett, "It is widely accepted that 'modern science' arose in the Europe of the 17th century (towards the end of the Renaissance), introducing a new understanding of the natural world."[89] In the 15th century, Portugal and Spain, two of the greatest naval powers of the time, took the lead in exploring the world.[106][107] Christopher Columbus reached the New World in 1492, and soon after the Spanish and Portuguese began establishing colonial empires in the Americas.[108] France, the Netherlands and England soon followed in building large colonial empires with vast holdings in Africa, the Americas, and Asia.
18th and 19th centuries
Napoleon's retreat from Russia in 1812. Napoleon's Grande Armée had lost about half a million men.
Main article: Modern history
See also: Industrial Revolution, French Revolution, and Age of Enlightenment

The Age of Enlightenment was a powerful intellectual movement during the 18th century promoting scientific and reason-based thoughts.[109][110][111] Discontent with the aristocracy and clergy's monopoly on political power in France resulted in the French Revolution and the establishment of the First Republic as a result of which the monarchy and many of the nobility perished during the initial reign of terror.[112] Napoleon Bonaparte rose to power in the aftermath of the French Revolution and established the First French Empire that, during the Napoleonic Wars, grew to encompass large parts of Europe before collapsing in 1815 with the Battle of Waterloo.[113][114]

Napoleonic rule resulted in the further dissemination of the ideals of the French Revolution, including that of the nation-state, as well as the widespread adoption of the French models of administration, law, and education.[115][116][117] The Congress of Vienna, convened after Napoleon's downfall, established a new balance of power in Europe centred on the five "Great Powers": the United Kingdom, France, Prussia, Habsburg Austria, and Russia.[118]
The Industrial Revolution started in Great Britain

This balance would remain in place until the Revolutions of 1848, during which liberal uprisings affected all of Europe except for Russia and the United Kingdom. These revolutions were eventually put down by conservative elements and few reforms resulted.[119] In 1867, the Austro-Hungarian empire was formed; and 1871 saw the unifications of both Italy and Germany as nation-states from smaller principalities.[120] Likewise, in 1878 the Congress of Berlin has conveyed formal recognition to the de facto independent principalities of Montenegro, Serbia and Romania.

The Industrial Revolution started in Great Britain in the last part of the 18th century and spread throughout Europe. The invention and implementation of new technologies resulted in rapid urban growth, mass employment, and the rise of a new working class.[121] Reforms in social and economic spheres followed, including the first laws on child labour, the legalisation of trade unions,[122] and the abolition of slavery.[123] In Britain, the Public Health Act 1875 was passed, which significantly improved living conditions in many British cities.[124] Europe’s population increased from about 100 million in 1700 to 400 million by 1900.[125] In the 19th century, 70 million people left Europe in migrations to various European colonies abroad and to the United States.[126]
20th century to present
Main articles: Modern era and History of Europe
See also: World War I, Great Depression, Interwar period, World War II, Cold War, and History of the European Union
European military alliances just prior to the start of WWI

Two World Wars and an economic depression dominated the first half of the 20th century. World War I was fought between 1914 and 1918. It started when Archduke Franz Ferdinand of Austria was assassinated by the Bosnian Serb Gavrilo Princip.[127] Most European nations were drawn into the war, which was fought between the Entente Powers (France, Belgium, Serbia, Portugal, Russia, the United Kingdom, and later Italy, Greece, Romania, and the United States) and the Central Powers (Austria-Hungary, Germany, Bulgaria, and the Ottoman Empire). The War left more than 16 million civilians and military dead.[128] Over 60 million European soldiers were mobilised from 1914–1918.[129]
Ruins of Guernica (1937). The Spanish Civil War claimed the lives of over 500,000 people.

Partly as a result of its defeat Russia was plunged into the Russian Revolution, which threw down the Tsarist monarchy and replaced it with the communist Soviet Union.[130] Austria-Hungary and the Ottoman Empire collapsed and broke up into separate nations, and many other nations had their borders redrawn. The Treaty of Versailles, which officially ended World War I in 1919, was harsh towards Germany, upon whom it placed full responsibility for the war and imposed heavy sanctions.[131]

Economic instability, caused in part by debts incurred in the First World War and 'loans' to Germany played havoc in Europe in the late 1920s and 1930s. This and the Wall Street Crash of 1929 brought about the worldwide Great Depression. Helped by the economic crisis, social instability and the threat of communism, fascist movements developed throughout Europe placing Adolf Hitler of Nazi Germany, Francisco Franco of Spain and Benito Mussolini of Italy in power.[132][133]

In 1933, Hitler became the leader of Germany and began to work towards his goal of building Greater Germany. Germany re-expanded and took back the Saarland and Rhineland in 1935 and 1936. In 1938, Austria became a part of Germany following the Anschluss. Later that year, following the Munich Agreement, Germany annexed the Sudetenland, which was a part of Czechoslovakia inhabited by ethnic Germans. At the time, Britain and France preferred a policy of appeasement.
Burned-out buildings in Hamburg, 1944 or 45

Shortly afterwards, Poland and Hungary started to press for the annexation of parts of Czechoslovakia with Polish and Hungarian majorities. Hitler encouraged the Slovaks to do the same and in early 1939, the remainder of Czechoslovakia was split into the Protectorate of Bohemia and Moravia, controlled by Germany, and the Slovak Republic, while other smaller regions went to Poland and Hungary. With tensions mounting between Germany and Poland over the future of Danzig, the Germans turned to the Soviets, and signed the Molotov–Ribbentrop Pact. Germany invaded Poland on 1 September 1939, prompting France and the United Kingdom to declare war on Germany on 3 September, opening the European Theatre of World War II.[134][135] The Soviet invasion of Poland started on 17 September and Poland fell soon thereafter.

On 24 September, the Soviet Union attacked the Baltic countries and later, Finland. The British hoped to land at Narvik and send troops to aid Finland, but their primary objective in the landing was to encircle Germany and cut the Germans off from Scandinavian resources. Nevertheless, the Germans knew of Britain's plans and got to Narvik first, repulsing the attack. Around the same time, Germany moved troops into Denmark, which left no room for a front except for where the last war had been fought or by landing at sea. The Phoney War continued.

In May 1940, Germany attacked France through the Low Countries. France capitulated in June 1940. However, the British refused to negotiate peace terms with the Germans and the war continued. By August Germany began a bombing offensive on Britain, but failed to convince the Britons to give up.[136] In 1941, Germany invaded the Soviet Union in the ultimately unsuccessful Operation Barbarossa.[137] On 7 December 1941 Japan's attack on Pearl Harbor drew the United States into the conflict as allies of the British Empire and other allied forces.[138][139]
The "Big Three" at the Yalta Conference in 1945; seated (from the left): Winston Churchill, Franklin D. Roosevelt, and Joseph Stalin

After the staggering Battle of Stalingrad in 1943, the German offensive in the Soviet Union turned into a continual fallback. In 1944, British and American forces invaded France in the D-Day landings, opening a new front against Germany. Berlin finally fell in 1945, ending World War II in Europe. The war was the largest and most destructive in human history, with 60 million dead across the world.[140] More than 40 million people in Europe had died as a result of the war by the time World War II ended,[141] including between 11 and 17 million people who perished during the Holocaust.[142] The Soviet Union lost around 27 million people during the war, about half of all World War II casualties.[143] By the end of World War II, Europe had more than 40 million refugees.[144] Several post-war expulsions in Central and Eastern Europe displaced a total of about 20 million people.[145]
The Schuman Declaration led to the creation of the European Coal and Steel Community. It began the integration process of the European Union. (9 May 1950, at the French Foreign Ministry)

World War I and especially World War II diminished the eminence of Western Europe in world affairs. After World War II the map of Europe was redrawn at the Yalta Conference and divided into two blocs, the Western countries and the communist Eastern bloc, separated by what was later called by Winston Churchill an "Iron Curtain". The United States and Western Europe established the NATO alliance and later the Soviet Union and Eastern Europe established the Warsaw Pact.[146]

The two new superpowers, the United States and the Soviet Union, became locked in a fifty-year long Cold War, centred on nuclear proliferation. At the same time decolonisation, which had already started after World War I, gradually resulted in the independence of most of the European colonies in Asia and Africa.[6] In the 1980s the reforms of Mikhail Gorbachev and the Solidarity movement in Poland accelerated the collapse of the Eastern bloc and the end of the Cold War. Germany was reunited, after the symbolic fall of the Berlin Wall in 1989, and the maps of Eastern Europe were redrawn once more.[132]

European integration also grew after World War II. The Treaty of Rome in 1957 established the European Economic Community between six Western European states with the goal of a unified economic policy and common market.[147] In 1967 the EEC, European Coal and Steel Community and Euratom formed the European Community, which in 1993 became the European Union. The EU established a parliament, court and central bank and introduced the euro as a unified currency.[148] In 2004 and 2007, more Eastern European countries began joining, expanding the EU to its current size of 27 European countries, and once more making Europe a major economical and political centre of power.

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Dhaka Hotel Girl's Mobile Number 2013 (Call girl)

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Make Money with the Microsoft Ad Control (Mobile Matters)

While some developers create mobile applications as a hobby or as a way to see their names in lights, for others it’s all about the money. As you may already know, the Windows Phone Marketplace offers a simple way to get paid for your hard work by selling apps to users. However, there’s also another, complementary way for you to make money from your Windows Phone 7 applications: advertising. The Microsoft Advertising SDK makes the process of incorporating ads into your apps easy—and you’ll get paid when consumers use your app, even if it’s free to download.
This article will:

• Show you how to get started with Microsoft Advertising in your application.
• Walk you through creating an advertising-supported app using XAML or in code—going from File | New all the way to Build and Run.
• Go beyond the basics to help you improve the advertising experience for your end users and make more money.

About Advertising

The reality is that mobile users are, for the lack of a better word, “thrifty.” Many who won’t hesitate for a second to spend $4 on a double latte will agonize over a 99-cent app purchase. Advertising enables you to still make money from those users who aren’t ready or willing to spend their hard-earned pennies to buy your app. Free apps, “lite” versions of paid apps and trials of paid apps all present ad monetization opportunities. Given that downloads of free and trial apps greatly outpace those of paid apps in the Windows Phone Marketplace, showing ads in your app is simply good math.
The Microsoft Advertising SDK is a free download and the service is free to use. Furthermore, the ads shown when you use the Microsoft Ad Control aren’t just from Microsoft adCenter. Instead, Microsoft has created a real-time ad exchange where top-tier mobile ad networks bid for the right to show their ads in your app. This improves ad rates overall and ensures that advertisers are paying top dollar for ads in mobile apps on Windows Phone 7. You get paid 70 percent of the revenue the ad impressions in your app generate monthly.
As you’ll see later in this article, using the Microsoft Ad Control is easy enough that even part-time developers and students are getting into the act of building ad-supported Windows Phone 7 apps. Your mileage may vary, of course; if your app engages end users and they use it often, the money-making potential goes far beyond pocket change. Many developers have made more from advertising than they have through app sales, and Microsoft has published a couple success stories that highlight a few of these experiences (bit.ly/9RlMFW).

Getting Started

Getting started with the Microsoft Ad Control is easy and, even if you’re still a novice Windows Phone 7 developer, you can be up and running in no time. Here are the steps to include Microsoft Advertising in your application:

1. Sign up on the Microsoft pubCenter portal with your Windows Live ID. Here you’ll be able to register your ad-supported applications and the locations within those apps where ads will appear.
2. Get the free Microsoft Advertising SDK for Windows Phone 7. Today, you can download this SDK from the pubCenter portal, but later this year you’ll get it automatically when you install the upcoming version of the Windows Phone Developer Tools.
3. Add the Microsoft Ad Control to your application. Set a couple of properties in the Ad Control to identify your app and ad location, and you’re ready to submit your ad-enabled app to the Windows Phone Marketplace.

Once your app is live in the Windows Phone Marketplace and starts getting used by end users, it will automatically start generating ad impressions. You’ll get paid for showing these ads on a CPM-basis (cost per thousand views; see “Advertising 101” for more on the cost breakdown) and after you’ve hit a minimum threshold of $50, you’ll automatically get issued a check or direct deposit—your choice—from Microsoft.

pubCenter Setup

Your first step in working with ads from Microsoft is to sign up at the Microsoft Advertising pubCenter portal at pubcenter.microsoft.com using your Windows Live ID (see Figure 1).
Figure 1 The Microsoft Advertising pubCenter Portal
You’ll be asked to enter some information about yourself or your company, then you can jump right in and register your first application and “ad unit.”
In order to define a new application in pubCenter, all you have to do is give it a friendly name. Later on, if you have more than one ad-supported application, you’ll be able to break out the statistics to see how the ads in each of your applications are performing.
On the same screen, you can also define your first ad unit. Each ad unit has a name and represents a location in your app where advertising will be shown. Ad units can be associated with up to three categories that best describe the content surrounding them (see Figure 2).
Figure 2 Registering Your App and Creating an Ad Unit
The categories you select will be one of the many factors that determine which ads are displayed in your app.
Once you click Save, you’ll see a summary of the information for your new pubCenter account and also the IDs for the application and ad unit you just created. When you’re ready to go live, you’ll use these values with the Ad Control to identify your app to the Microsoft Advertising servers.
At this point, you’re done with pubCenter for the time being and are ready to dive into Visual Studio. You can return to pubCenter at any time to define more applications or ad units, see in-depth advertising reports and configure advanced settings such as competitive exclusions.

Adding Ads with Visual Studio

If you’re not using the latest Windows Phone Developer Tools yet, you can download the newest version of the Microsoft Advertising SDK from pubCenter. This SDK includes the Microsoft Ad Control as well as documentation and code samples to help you get started. The June 2011 version of the Ad Control offers rich media support and an improved API set. Make sure you have it installed so that you can follow along. Let’s look at how to use it from the Visual Studio Designer.
Start by creating a new Windows Phone 7 Silverlight project with File | New, and opening up the XAML surface where you want to show ads. Pick a suitable spot where the ad can be frequently shown, but won’t annoy the user; typically, the bottom or top of the screen is best. Drag the AdControl (note: “Ad Control” refers to the Microsoft product, while “AdControl” refers to the class or object) directly from the Toolbox pane to add it directly to a Grid control (see Figure 3).
Figure 3 Placing the AdControl
Once the AdControl is on the page, you need to set some properties for it to work correctly in your application. First, you’ll need to double-check the width and height of the AdControl. It’s recommended to keep the control at the standard dimension of 480 x 80 pixels for mobile ads. Setting a smaller size will prevent standard-sized ads from being displayed on your page. Setting a larger size will mean that there will be some empty space between where the ad is rendered and the border of the AdControl.
Next, you’ll need to link the AdControl with the Application ID and Ad Unit ID you created in the pubCenter portal. It helps to have the portal Web page open so you can copy and paste these values into the Visual Studio window.
Finally, there are two properties you’ll want to set to meet your app’s needs. If set to true, the IsAutoRefreshEnabled property automatically shows a new ad every 60 seconds. This enables you to increase the number of ads a user sees, which should lead to better revenue for your app (see “Advertising 101” for more on ad revenue). Set the IsAutoCollapseEnabled property to true if you want the AdControl to automatically hide itself from view before an ad is downloaded.
The XAML generated by the Visual Studio Designer should look something like this:

<Grid x:Name="ContentPanel" Grid.Row="1">

  <my:AdControl

    Height="80"

    Name="adControl1"

    Width="480"

    IsAutoCollapseEnabled="True"

    IsAutoRefreshEnabled="True"

    AdUnitId="test_client"

    ApplicationId="Image480_80" 

  />

</Grid>

Now hit Run to see your first ads.

AdControl API

If you’re finding that you want to do some fancier things, such as controlling the hiding or showing of ads, or you want to have a bit more control over when the ad shows in your application, you can chose to instantiate the AdControl directly in your code.
But before we get there, let’s start by dissecting how the AdControl works (see Figure 4). Behind the scenes, when your app starts and the AdControl gets initialized, it requests an ad from the Microsoft Advertising servers. The request is formed with the Application ID and Ad Unit ID that you specified in your code.
Figure 4 How the AdControl Works
It’s critical that this information matches what you copied from the pubCenter portal or to the test IDs provided in the documentation. The request also contains some other useful information about your app, such as the region to which ads will be matched.
If the ad it receives back uses images or HTML-based rich media, the AdControl will reconnect with a Web server to download the advertising content (such as JPEG, GIF, HTML or PNG files). Once the user has seen the ad, the AdControl may connect again with the server to record the ad impression. This whole cycle repeats when the ad gets refreshed and a new ad gets downloaded.
There isn’t much in the way of rocket science when it comes to the code required to use the AdControl. You’ll need to start by adding the Microsoft.Advertising.Mobile.UI assembly as a reference in your project. You’ll also want to add a using statement for the Microsoft.Advertising.Mobile.UI namespace. And in your page’s constructor, you’ll place the code to create the AdControl. You’ll then need to add the AdControl instance into the page’s visual tree. In this case, we’re adding it to a grid that we have in our layout (see Figure 5). With the code in Figure 5 in place, your app should be ready to build and show ads using the code you’ve written.
Figure 5 Adding the AdControl to the Visual Tree

using Microsoft.Advertising.Mobile.UI;
 
 
 
// Constructor
 
public MainPage()
 
{
 
  InitializeComponent();
 
 
 
  AdControl adControl = new AdControl();
 
 
 
  // Add the control to a grid control
 
  Grid grid = (Grid)this.LayoutRoot.Children[1];
 
  grid.Children.Add(adControl);
 
 
 
  // Insert real values from pubCenter before
 
  // submitting your app to Windows Phone Marketplace!
 
#ifdef SHOW_TEST_ADS
 
  adControl.ApplicationId = "test_client";
 
  adControl.AdUnitId = "Image480_80";  
 
#else
 
  // Use your real Application ID and Ad Unit ID here
 
  adControl.ApplicationId = "12ab456c-de7f-89ab-0123-4567890c1d23";
 
  adControl.AdUnitId = "12345";
 
#endif
 
 
 
  // Make the AdControl fit the standard 480 x 80 dimension
 
  adControl.Width = 480;
 
  adControl.Height = 80;
 
 
 
  // Let the AdControl collapse and refresh automatically
 
  adControl.IsAutoRefreshEnabled = true;
 
  adControl.IsAutoCollapseEnabled = true;
 
}

Tips and Tricks

Here are a couple of important things to keep in mind when working with the AdControl in your app, and a few ways—such as targeting— that will help you maximize the value of the advertising in your app.
First, always make sure you can see both “test” and “real” ads running in your application. To view test ads, set the ApplicationID to “test_client” and Ad Unit ID to a standard test value such as “Image480_80.” A well-placed #ifdef can come in handy here. You should use test ads while developing and testing your app, but once you’re ready to release, it’s critical you set this back to your pubCenter-issued Application ID and Ad Unit ID. However, testing with your own app IDs is important because it ensures your application works with “real” live ads.
Next, to get the best ads, it’s important to provide as much information as possible to the ad system. The AdControl often gets this information automatically, so your application manifest must have the following capabilities:

• ID_CAP_PHONEDIALER
• ID_CAP_NETWORKING
• ID_CAP_WEBBROWSERCOMPONENT
• ID_CAP_IDENTITY_USER
• ID_CAP_MEDIALIB

If it makes sense for your application, it’s also recommended to use the ID_CAP_LOCATION capability. Enabling location-based advertising improves the quality and relevance of the ads that your users will see.
The AdControl.PostalCode and AdControl.Country properties allow an app to update the user's location.  In the following example, a Beverly Hills movie star app would generally know that its users are around that location:

using Microsoft.Advertising;
 
// Make sure the AdControl is created
adControl.Country = "US";
adControl.PostalCode = "90210";

Similarly, it might also be useful to handle a few things about the ad experience in your code. If you’ve set the IsAutoRefreshEnabled property to false, then you’ll be able to refresh ads manually. Call the adControl.Refresh method to bring a new ad into view, but make sure not to call it more than every 30 seconds in order to give users enough time to click on ads they might be interested in.
If you’ve set the IsAutoCollapseEnabled property to false, you can listen for an ErrorOccurred event. This event will fire whenever an ad fails to download or display. You can use this event to collapse the AdControl and reclaim that space for use by your application’s other UI elements. When the AdRefreshed event fires, you’ll know a new ad is ready to be seen and you can restore its visibility (see Figure 6).
Figure 6 The AdRefreshed Event

public void AdControl_AdRefreshed(object sender, EventArgs args)
 
{
 
  AdControl ad = (AdControl)sender;
 
 
 
  Dispatcher.BeginInvoke(() =>
 
  {
 
    ad.Visibility = System.Windows.Visibility.Visible;
 
    Debug.WriteLine(
 
      "ad control '" + ad.Name + "' got ad, visibility = " + ad.Visibility);
 
  });
 
}
 
 
 
public void AdControl_ErrorOccurred(object sender, AdErrorEventArgs args)
 
{
 
  try
 
  {
 
    AdControl ad = (AdControl)sender;
 
 
 
    Dispatcher.BeginInvoke(() =>
 
    {
 
      ad.Visibility = System.Windows.Visibility.Collapsed;
 
      Debug.WriteLine(
 
        "error in ad control '" + ad.Name + "': " + args.Error.Message);
 
      Debug.WriteLine("ad control '" + ad.Name + "' visibility = " + ad.Visibility);
 
    });
 
  }
 
  catch (Exception e)
 
  {
 
    Debug.WriteLine("oh no! " + e.Message);
 
  }
 
}

As you’ve seen, using the AdControl in your application is easy. And if you run into trouble, there are generally only a few things that can go wrong and cause ads not to be shown:

• No network connectivity
• Typo in Application ID or Ad Unit ID
• The user is in a location where ads from Microsoft Advertising aren’t available
• The AdControl is set to a dimension that’s too small
• Missing capabilities

Finally, if you’re writing a game and want to use XNA, look at the Microsoft Advertising XNA advertising game component that’s also part of the Microsoft Advertising SDK. Unfortunately, there isn’t enough space to go in-depth on XNA in this article, but there is documentation available online at search @ google or bing.
Now go add some advertising and start getting paid for all that hard work you put into your application!