It doesn't seem like it would be hard, but if the rankings aren't driven by money, then there will be attempts to game the system. The problem I feel is Money. As long as everyone has to compete for it (meaning money doesn't work for the people, people work for money - in a system owned by the few), we'll have shady marketers, shady products, spammers etc... so, I think that it will remain a cat and mouse game.