The best time to promote bounties are on altcoins season ,if you are tired of one delay after the other just quit till altcoins season returns ,this is the reason why 2017 was the best year for bounty hunters
Hmmm. How do we exactly know when is this altcoins season? So far, we can't be 100% certain when is the good time to promote bounties. Because even the projects you do not expect to do well end up doing well. I just conclude that promoting bounties is just grace. The one to pay you will definitely pay you huge.
There might be a best time to promote a project but the odds of becoming certain to the exact date cannot be easily determine. What we should focus more is to promote a project that is worthy enough of advertisement. Those project that the people needs at the present time. In this case, the time for promoting bounty projects depends on the needs and requirement of the community. If we think that a particular project is beneficial, then promote it. If we can see a project can solve a massive problem to the society, then promote it. The idea is, Always promote projects that are having a potential to provide benefits rather than promoting projects that only aim to gather investment without practical purpose.