The Network is the Market. Tribe.net is a Craig's List meets Friendster style Social Networking Service that is just coming out of beta. What's different is the explicit transactional nature of the network, emphasis on tribal organization tools and how it relies on social capital… [Ross Mayfield's Weblog]
so here is my thought on social networks from yesterday. by creating barriers to entry, effectively what social network systems on the internet are doing is creating the same social situation as the early internet where technological barriers kept communities small and thus encouraged more interaction amongst the people in them.