Danah Boyd has written an excellent essay on why MySpace has succeeded where Friendster failed. In one paragraph:
Basically, MySpace evolved with its users, building a trusting relationship, figuring out how to meet their needs and cultural desires, providing them with features and really trying to give them what they were looking for. Friendster did not - it fought its users hand and foot, telling them how to behave.
And if you don't know Danah Boyd....
