When you participate in an airdrop campaign, you will get a referral link that you can use to spread the word about the campaign and get extra tokens. You will receive half the airdrop reward for each new user that joins the campaign through your link, becoming your referral.
-Each claimed airdrop generates new referral link that's linked to that airdrop. The link will become invalid once claimed airdrop ends. New participants to an airdrop will also receive their referral link by Email.