It is hard to determine which bounty is really fake or scam. Even the good ones failed and branded as scams. So i think to make it clear which bounty will be going to give you the real reward is by observing how their team had been making promotions. Some ICOs had teams that are so active that they really spent sometime for it and not just display it on the web. The team are well known and their personalities as posted in their websites are revealed correctly such that all other informations are available. You wouldn't be expecting a bystander or a person connected to many illegal activities be so active in making ICOs and sincerely offering his time and effort. So its a matter of knowing them. Maybe this will help in choosing the right bounty.