As per the things we are seeing from the past the Airdrops are completely useless which we don't make money through these airdrops. Some times it is impossible for us to sell the coin which we get through Airdrops, so instead of wasting our precious time in Airdrops better concentrate on best bounty campaigns.
Completely useless? No way. I am participating in a bittorrent airdrop and it is worth a few dollars. And this is not even to mention airdrops I have seen in the past year that actually managed to gain a bit of value (I still hold of course:)),,, but I do agree, do not work too hard for airdrops. Get them if you like them, get them if you think it is easy and you could partake in the project one day. But not for anything less than this!