The first social network to be launched was SixDegrees.com in 1997. SixDegrees was the first site to allow users to list friends they may have in their own network. Although SixDegrees had millions of users, it ended up closing in 2000. It was unable to transform itself into a viable business. Between 1997 and 2001 there were many other systems that supported public profiles, and allowed people to show their list of friends. These included BlackPlanet, and MiGente however many of these were used as dating profiles.

It was not until the introduction of Ryze.com in 2001 that Social Networking Sites began to take off. Ryze was introduced by its founder to the San Francisco business community to people who then went on to invest in further Social Networking sites. According to Boyd and Ellison in their article entitled Social Network Sites: Definition, History, and Scholarship the people involved in Ryze, Tribe.net, LinkedIn and Friendster were interlinked personally and professionally. However in the end they all went their separate ways.

fonte: The Origins of Social Networking, COM917J2 Blog 25/02/08