I think the most profitable part from bounty is Airdrop specially for those good projects , Secondly signature campaign for coins has its own chain like the one i am using now not as waste of time tokens which easy to built on eth blockchain as smart assets .
Some social media campaigns like twitter or Facebook are profitable too and come in third place .
Airdrop is waste of time. And you will need a lot of time to earn something (2-5 dollars is not income)
Own blockchain is not an indicator of project reliability.