the airdrop for me its super profitable to gained money, even its all free but you need also to support them, what i mean is if you buy some token or coin for better,. i know they dont yet if they success the project i just suggest its get to support them, even its small money you spend in that project but soon your spend money to his project your profit make 3x income.
I think a really low percentage of airdrops can give profit. Because many of them are born dead. Unfortunately, a really big part of them are useless and waste of time.