There are many ways to earn and get profit like Airdrop and joining the bounty campaigns like social media facebook, twitter, medium, reddit, and telegram. But the most paying is when you join the signature bounty campaign if you completed all task you will get your earning or tokens. Then you can either hold it or sell it.
The most paying is depending on the shares which were giving by the project owner. I saw there are so many project that they're focusing about the social media like youtube, twitter and facebook then signature campaign.
So it's just not right if you're saying signature has the the most paying.