MSE allows users to offer bounties to reward great answers, but the only mechanism in place to reward great questions is upvotes. Do you think questions should also be rewardable with bounties too?
I saw this bounty question this morning. What impressed me is not the problem itself, but how the asker presented his/her failed efforts to tackle it. Most of us complain that many users just copy their homework problems from textbooks verbatim, without showing even any slight intent (not to mention effort) to solve the problems on their own. Some users did show their works, but to be honest, some of their works are so messy that I think a plain "please do my homework" question is even better.
At any rate, we almost never tell those users any good example of a question where the asker's efforts are well presented.
If questions are rewardable with bounties, bounty offerers can leave their reasons for the bounties in comments, and we can tell the others that "look, in this question, the asker's effort to solve the problem is so well presented that someone had even shown their appreciation by rewarding the question with bounty!"