in my early stage on joining this forum and start to participate signature and other bounty campaigns I had joined almost all airdrops available in this forum because I want to earn free tokens, coins and money but I faced too many issues because most of them aren't paying and most of the paying airdrops doesn't hitting coin exchanges and coinmarketcap.com.
But still there are some free tokens that I get from airdrops.
If you want to earn money on airdrops, just do the same. join every airdrops available in this forum and you will earn money from some good airdrops.