You are correct most of them are scam. The Airdrop project owners are thieves who are only interested in the donation they will get from unsuspecting hunters that will donate their hard earned Ether which they claimed to be used as gas or a support their effort in listing their scamming token. 
Thanks...so you take me for a thief???
Do not forget that i give the opportunity to get free WSPU2 and you are not to take them if you do not want.
I'm the only one airdrop projector who allows to trade the free WSPU2pts directly for dollars.