Basically this would be the only way you can do without any risk, you'll just have to meet tgeir demand from you, but having a low rank would not give you anything. Joining bounty has just no assurance whether the join you have joined in is actually real and promising. I qoykd say that joining such campaign is also like buying coin, its just that you exchange something from your effort. So just as you are making choice on buying coin, do it the same as joining a campaign.