Tribe.net
Tribe.net (often shortened to "Tribe") is a website that hosts a online community of friends, similar to Orkut or Friendster. Anyone may register as a new Tribe user, and may then define his or her immediate network of friends, either by choosing from existing members or by inviting new members to join. Each of these users may in turn define their own network of friends. (This process results in a type of user-driven viral marketing on behalf of Tribe.net.)
As more and more people and their friends join Tribe, it results in an elaborate social network with tens of thousands of members. Tribe users leverage the small world phenomenon as a way to enhance their own immediate social network. As of March 2004, the population of Tribe is skewed heavily towards people living in San Francisco, though the geographic distribution is gradually normalizing as people from other places join.
Tribe.net features many tribes, a kind of topical forum. A new tribe may be created by any registered Tribe user. When a user creates a new tribe, that user is the moderator of the tribe. Any user may in principle join any tribe, although some tribes are private or require permission from the tribe moderator to join. In addition to threaded messages, members can use tribes to announce upcoming parties, concerts, business icebreakers, or other events easily and reach select audiences. Currently there are thousands of tribes, with more being added daily.
The company behind Tribe is privately owned, financed largely with venture capital. Tribe has partnered with the Washington Post and Knight Ridder, which are marketing Tribe in their local classified ad businesses.