Another trick of marketers. Free to get, it means doing nothing, no effort. And then you want to invite, to wait when he will buy and you will receive free not$ 12, but will receive a referral reward. This is direct advertising on the forum. In the furnace of this topic and thread.
I'm seeing a lot of airdrops now. And I mean a lot. That aren't actually airdrops anymore. I mean, where I came from, airdrops meant free, like you said. Costs nothing. Some effort maybe required in registration although I recall the true airdrops actually didn't even need you to do anything except link an account, which was like seconds. Even Viuly airdrop literally required nothing. You received it whether or not you wanted it. Need to kill all these false airdrop promises.