Much more than personal information, what facebook can monetize is identity & relationships. For example, with Facebook Connect, it's much harder to be an anon

Much more than personal information, what facebook can monetize is identity & relationships. For example, with Facebook Connect, it's much harder to be an anonymous troll commenter on a blog. And maybe using Facebook Connect as a login for eCommerce sites would reduce the amount of fraud those sites have to deal with. That is definitely monetizeable.