Bottom Line: The bounty is to generate interest and answers for your question, it does not necessarily guarantee that one of those will be the right answer.
Consider bounties to be paying for advertising. Once you've purchased an ad spot, you can't get your money back just because no one bought your product.
Also, if it becomes obvious that your question is unclear then you should edit it for clarity. This has the added bonus of popping you to the top of the active list as well, which would generate extra interest.
If after adding a bounty, you are still unable to get a valid answer to your question, perhaps your question is unclear or unanswerable. You should be editing the question to incorporate any feedback you have received from users.
What happens if there's no answer after the bounty period?
What happens if I feel my question is still unanswered?
What is automatic awarding?
At the end of the bounty period, if the bounty starter has not manually awarded the bounty, eligible answers can be automatically awarded half the bounty amount. The criteria for an answer to be eligible for automatic awarding are as follows:
* The answer must be given after the bounty was started
* The answer must have a score of at least +2
If two or more eligible answers have the same score, the oldest answer is awarded the bounty.
If no answers meet these criteria, the bounty ends without it being awarded to any answer, and is not refunded to the bounty starter.