A bounty is a process whereby someone who are involved in a particular bounty try as much they can to promote a signature campaign, so in what I have noticed so far is avenue of making their projects to be known,  and the management will have an option where you share the link of the project, in which it can be reddit and it can be Facebook and twitter and telegram, so on the process during this functions to promote the project after the end of the project they will be a specific amount that will be distribute and before then you have already accepted or abide on the rules and the regulations of the campaign.