One time airdrops worth 5$ (or at least it is said that it is worth that much) are probably mostly a waste of time. But there are airdrops in which you can get a huge amount of coins in several airdrops, but you need to participate and do something for the community. That was the case of Deep Onion (I am wondering how much money you could actually make when one Onion was for 16 $), now I hope it will also be the case for Privcy.