The title of this thread is bit provocative, but the fact is that most people have a bad experience with airdrops. According to several airdrop hunters I spoke to, the majority ICOs don't pay out at all.
What's your experience with airdrops? Did you get scammed most of the times?
This is something most people are still not wary off. Don't perform every airdrop you see. The chances of you getting paid are very slim. Also, the companies no longer give good rewards for the airdroppers.