(Potentially relevant link)

Yahoo! Answers is funner than Google Answers because it has points. XP like E2, essentially. Unfortunately, it sucks big time. This is for several reasons, most of which boil down to lack of accountability. If you look at ten random questions, you'll likely find at least that many incorrect answers, and probably a fair number of 'i dont know'/'look it up's. The people posting such answers get two points for it, and lose nothing for being wrong or unhelpful. You can't downvote the person claiming only three countries ban flag desecration or the morons claiming allosaurus or tyrannosaurus rex as the largest meat-eating dinosaurs or claoming infinity is the largest prime number. Only occationally will you find the incorrect answer being chosen as best answer (an exta ten points), but posting an obviously incorrect answer shouldn't gain you any points.

In addition to the idiots giving and voting for incorrect answers, there's a more prevelant problem--though perhaps a less troublesome one: multiple (often ten+) people will post the same (correct) answer to a question. And I don't mean nearly at the same time so perhaps they didn't see the earlier answers. They can be hours apart, and the same one-word answer will be posted again and again. It's essentially spam, but not considered so by Y!A.

A third problem is that there's little to no community cohesion. On E2, I knew the people and they were--for the most part--friendly. On Y!A, people are relatively unknown and more often trolls than anywhere but Usenet.

Y!A's moderation is this: major abuses get deleted and good (and some bad) answers get extra points. But I could probably gain thousands of points a day just by doing what most people do: post the same, one-word, useless answer as everyone else on simple questions. The primary thing Y!A needs to change is moderation. Punish incorrect and repetetive answers instead of rewarding them.

Oh, and while I'm complaining, it's filled with useless/poorly-formed questions. But that's not quite so bad since you don't gain points for posting questions. (Actually, you lose them, but then regain them when you pick the best answer)