From my observation concerning bounty campaign. I know that those projects that comes to bounty service or section are merely for earning and advertising the project. And i know vividly that such projects funds is been allocated to the bounties. And the process of knowing a good bounty campaign, it's primarily depends on the manager of the signature campaign that will quickly know a scam campaign.
A good manager must have done research beforehand on the campaign project that he will handle.
In the case of altcoin bounty boards, we can see a lot of new bounty managers, who certainly don't have that reputation.
some good managers have also made mistakes in project analysis. even some projects also end up scams. I know it's out of the bounty manager's control. they do their best, but if the project ends up being a scam and running away, it's not 100% the bounty manager's fault.
I'm sure most bounty hunters never research projects that do bounty campaigns. most of them just sign up. run errands. then blame the bounty manager when the project turns out to be a scam.