The bounty manager(s), the thread author and the project owners are three independent entities. The bounty manager(s) and the thread author are facilitators and not the bounty-issuers. They will not be held liable in the event of a breach of contract by the bounty-issuer or failure to fulfill their obligation. Facilitation is NOT an automatic endorsement of product or service being offered, unless explicitly stated. We reserve the right to change the campaign at any moment, and reject people based on our judgement.
Both of them are effective imo the only difference that i've experienced between the two is that there's less moderation on the side of bounties compared to signature campaigns.