I think bounty earning are great incentive but differ from project to project.
Best paying bounties are generally happening in good performing coins, not on ico level but on market level. For examople if you join bounty for a coin that enters binance, you can get unbelieveably high amount of money.
Not all coins, it depends on the market situation, example, for now we cannot expect we will see automatically it will increase once listed in Binance,
some can easily manipulate, I have my bounty token and it entered in Binance but it has dump, that token is PundiX (NPXS).