Airdrops are up in the air for grabs. No investment, no need for advertising them for about a  month or so. All you need is a little time to fill up the registration form but do it with an extra care because you might be filling up a phishing form that would steal your information. If you can be sure that you're doing the safe thing, then it don't matter if that Airdrop is fake or not because you lose nothing though. But if that's a legit one, then lucky for you if you can receive some of their tokens.