Grew from college to college Facebook was set apart from other social networking sites in that it grew from college to college, using a dot-edu email address as verification of a new users identity and collegiate aliation.

Other services did not have explicit divisions within the overall network, nor an expansion strategy that targeted colleges. Facebook allowed users to restrict who could access their profiles: friends, friends of friends, and certain networks of users.

Facebook hit 1 million users in December 2004. By May 2005, the site had 2.8 million users at more than 800 colleges.

Its growth reportedly sparked a bidding war among a dozen venture capital firms eager to participate in Facebooks success. The winner was Accel Partners, which invested $12.7 million in a deal valuing Facebook at $100 million. Thrilled, Accel partner Jim Breyer praised the Facebook management team as intellectually honest and breathtakingly brilliant in understanding the college student experience.

Features

Each new feature tacitly invited speculation about Facebooks strategic intent in creating and releasing it. For example, when Messages launched, many wondered if it would ultimately be an e-mail killer. When Usernames launched, observers speculated that Facebook would soon supplant or replace independent business websites.

When Facebook announced Open Graph in April 2010, pundits immediately hailed it as a clear eort to make Facebook the centerpiece of any individuals Web experience.Launched with 30 external site partners,. It allowed users to Like external content, such as a news article on CNN.com, and that activity would be treated just as a Like was within the Facebook site, i.e. published to users walls and News Feeds. Users friends would also see on the article itself on the external site that the user had Liked it. Open Graph spanned news articles to e- commerce sites, movie and music sites, sports teams, and more. Crucially, Open Graph allowed users to individually opt in to each external site and allow activity on it to be announced back to Facebook.

Analysts concluded that as a result of Open Graph: Facebook can essentially build a database of anyones Likes that ranges across all categories. Most importantly, because of Facebooks focus on authenticity, the suggestions generated by Facebooks database are much more likely to be useful to a user (and advertisers).

F8 Platform

Facebook launched a platform called F8 in May 2007 for developers to build applications that could run within the site.

F8 allowed third-party developers to create applications that users could then add to the six standard Facebook applications: photos, events, groups, gifts, birthdays, and marketplace (also launched in May).

F8 launched with 85 applications from 65 partners including Microsoft and Amazon. By June 2007 40,000 developers had launched more than 1,500 new Facebook applications.

Zynga launched what is considered its best-known game, FarmVille, on Facebook in June 2009,[9] reaching 10 million daily active users (DAU) within six weeks.[10] As of early January 2013, Zynga games had over 265 million monthly active users (MAU),[5] and three of the top five Facebook games (in terms of MAU, according to AppData) were Zynga titles: FarmVille 2, Texas HoldEm Poker (now known as Zynga Poker), and ChefVille.[11] According to the BBC, around 80 percent of Zynga's revenue comes from Facebook users.

Users metadata (Facebook Social Graph)

Zuckerberg introduced to the public, a concept called the social graph as foundational to the Facebook user experience and to the sites growth potential.

Zuckerberg described Facebook as the largest social graph in the world.

On pace to hit 50 million users by the end of 2007, Facebook was adding 100,000 new users a day.

The company had a record of all the links among its members, as well as the members links to sites and places outside of the network.

This data constituted Facebooks social graph, a highly leverageable asset for Facebook and a tremendous advantage it had, that the other companies seeking to reach anyone who was in the Facebook network.

Simply put, Facebook had more information about peoples relationships and preferences than any other business did. Moreover, it was voluntarily given and highly reliable. Zuckerberg described:

"The Facebook platform is optimized for building applications in Facebook, and with more value for people to develop on our base than we could do on our own. People are already building social apps, but they have to reconstruct the social graph all by themselves. We are going to allow developers worldwide to do complete new things. Today social networks are completely closed nets.Today we are going to end that. With this [framework] any developer worldwide can build full applications on top of the social graph inside the Facebook Platform.