It is very difficult to predict or confirms that which one Bounty will be successful.
According to me if you want to find a good Bounty campaign, then make a good research about their product uniqueness, their bounty managers profile, quantity of coin & costing of coin and their strategy for project success.
After that invest your precious time and money in that project, but if feel not good about that, then just left it and search about other bounty campaigns. And always make good research about the project before joining in any bounty campaign.
AT the expense of good research you're right! Because to take part in the bounty program or invest in ICO, you need to carefully study the project. After taking part in scams you will lose time. And if you invest in a Scam company you will lose your funds. Study the white paper, the composition of the team, bounty managers.