Social networking sites are currently dominated by Facebook, which celebrated its 600 millionth profile creation in January 2011. The earliest social networking sites -- Myspace, LinkedIn and Bebo -- are still active, but the two dominant ones in terms of world traffic are Orkut and Facebook, both of which launched in 2004.
According to NetTrends reports, Orkut's first network traffic arrived in late January 2004, while Facebook's first traffic arrived in early February 2004. This means Orkut launched a week or two before Facebook did.
Initial User Groups
Orkut was developed by Google software engineer Orkut Büyükkökten, and the site is named for him. Originally, like Gmail, Orkut was meant to be an invitation-only service. Facebook was launched by Mark Zuckerburg as a follow-up to a programming project called FaceMash at Harvard. Initially, Facebook's userbase was limited to Harvard students, then other students at prestigious universities, then all college campuses, followed by a high school rollout. After the high school rollout, Facebook's entry requirements were loosened to a valid email address and a certification that the user was over the age of 13.
Facebook is by far and away the dominant social networking site on the Internet as of the date of publication, but this wasn't always the case. As recently as 2007, Orkut and Facebook had similar Web traffic statistics; Facebook started pulling away on total Web traffic in the 2008 timeframe, though Orkut remained more popular than Facebook in some countries, most notably India and Brazil. One of the reasons why Facebook has grown explosively is it offers account integration with Orkut; it's possible to access your Orkut friends and contacts from within Facebook.
Future of Orkut
Facebook has recently passed Orkut as the most popular social network in India. Current usage trends in Brazil indicate Facebook is adding users at a much greater rate than Orkut is in Brazil. While Google has said it will not shut Orkut down in the foreseeable future, it has launched another "social networking" style service with Plus One, which lets users tag search results they find useful, which will make them rank somewhat higher when friends in their social network run similar searches. Google is also publicly discussing something called the Google Social Experience, but as of the date of publication, details have not emerged beyond the title.