The rules are not clear enough, how you will track the people? Payments to random people? What? I think you should clarify the rules and how to participate correctly.
this persons want to have many subscribers by having this bounties.
They are not saying how many persons will win the $15 USD rewards for subscribing.
That 10000 USD rewards is just attempt to make people confused and just join the bounty without understanding the rules.
And base on the OP the campaign is ended already so who win the rewards ? Why not announce it publicly.