When I decide join a bounty campaign, I consider in some criteria: kind of bounty I can run, how, quality of it, and, the best important - is POOL of bounty and QUANTITY of participant. It's two element decide how many token you can receive.
Although the pool of the bounty is large, you can not make much money, because over time the percentage of your stakes will be smaller. Also the bigger the pool, in my opinion, it's the junk projects, because new junk projects can offer a huge pool, it's too pointless for potential projects.