This is the difference between good bounty managers and ordinary ones. A good one will hire a person, for a small fee, who will check all social network participants for the quality of the content and the quality of the services provided.
A good project does not need useless marketing; it needs a precise and high-quality presentation of itself through bounty hunters.
Is there really a way to check the quality of the work of the bounty hunter if their only task is to like or share in social media? I don't think that there is a need for that quality check. What they need is to limit their bounty participants to at least give them enough opportunity to receive more rewards.