Last week, I tried to open a bounty for a Stack Overflow question of mine. Unfortunately, there was only one answer posted, and it's not been helpful (mostly posting results to some Google search which I had obviously already done myself).
Today, I received an e-mail notification that the top-rated answer "may" be auto-accepted once the bounty expires. This confuses me, and searching here on meta hasn't really made it any clearer.
What criteria are used for auto-accepting an answer? If something does not answer the question, it should never be accepted, imo. I gave the guy an upvote for effort, but since it doesn't help me at all, it seems unjustified to award him a 250 point bounty?