ICOs already have IBOs very often to promote themselves. It's happening right here on Bitcointalk too, having ICOs throw around with millions of dollars for their IBOs. These IBOs often includes Signature campaigns, article writing, translations, social media promotions, etc!

However, an initial bounty offering using purely bounties and no sale is interesting, though I'm kinda sceptical about how they'd make their money... Projects still need money, even when a lot of human work is provided to them...

These articles lack readily available information about that.