Valueless Network
This E-Commerce News article has it about right:
Telling the truth -- no, I don't want to be your friend -- is uncomfortable, so most people acquiesce. But the worth of networks built on such dubious or unwanted connections likely isn't terribly high. "I'll get friend requests from people I haven't spoken to in over a year," says Wade Tinney, a sometime Friendster user and co-founder of video-game company Large Animal.
These social networking sites will always run into depreciating value of the node links, and, sooner or later, some nebbish spam-bombing the network and turning everybody off to even healthy networking behavior.
Bubble bubble.
