I think 60% is scam,most of the scam airdrop want donation,private key,and information about our details.
When the time i see that kind of airdrop i ignore not to sign up. Be carefull next time dont give your private key to anyone,because sometimes other member give or put there private key in form of airdrop. And then my experience in legit airdrop i think is good,they give free token and eran more if you have more refferals