It is necessary to choose the bounty very carefully. I'm looking for all the information about the project. Social networks and I read white paper. I look at Linkedin, the profiles of the founders of the project, their previous experience. It takes a long time, but it's better than disappointment later.
Yes, I agree with you. We have to choose bounty carefully. We need to read bounty's information as much as possible if else we will just waste our time for nothing. These are my experience when choose a bounty to join:
1. Project has a clear web site.
2. Manager have experience (I refer manager is Chinese or Korean) .
3. Has a good road map
4. The target is not too big, the best is it has reached the softcap