It sais airdrop but it is more like a bounty, because when you want to join it you need to fill out a form and in that form it asks for your twitter account and wants you to do a tweet with a mentioned quote for their promotion, just like a regular bounty twitter campaign. Not everyone has twitter or even wants twitter. Either do a regular normal airdrop or just say it like it is, not free airdrop since you need to put in an effort.