Well, the obvious is to get answers. To be more specific, sometimes people want answers from people NOT connected with the actual situation, to be sure people (as your friends might) aren't just telling you what you WANT to hear, instead of what you SHOULD hear. Or to get a wider range of opinions that you can get from those around you.
because they either want someone else's perspective, advice and maybe don't feel comfortable talking about it with others. I know I do it a lot, I just come on here and search a question and it helps, so.. ya! (: