There is space for competition in that area. StackExchange is pretty good, but since they don't allow questions with subjective answers, they basically exclude themselves from the vast majority of the market share. Then there is quora, yahoo answers, ... There is certainly enough space for a few good startups.
StackExchange leaves a lot of open opportunities even in the areas they focus on. The objectivity mantra means they'll ban "best programmer jokes", perhaps understandable, but oddly they'll block questions like "best database for X, best book on X" as being "Not Constructive". (I could understand "subjective", but I can't see how it's not useful data.)
So when I see things like this, it makes me think there's surely an opportunity and the opportunity falls squarely in Quora's lap. But depending how they execute on it, they might still be leaving the space wide open for others.
Reddit has some decent subreddits devoted to questions/answers, but the really good ones, like askscience, only allow objective answers. On second thought, that's probably why those ones are good.
