Yes... It's stated on the whitepaper that for one to become a member, you must hold seed token on the superbloom platform. And u can't get airdrop if you are not a member of superbloom platform.
Yes, you have to register on their website and hold SEED tokens on their platform in order to be eligible to receive free airdrop tokens.
people have to register first and buy SEED tokens also to get free Airdrop tokens? If yes, this is a good strategy from Superbloom.
If that's it, I don't totally see it as airdrop since you are required to buy token first. It's obviously like a bonus for their investors. By the way, what amount of token does one really need to hold to qualify?