How it works
The project defines the snapshot criteria: addresses that interacted with a specific protocol before a date, holders of a particular token, or wallets meeting an activity threshold. At the snapshot block, balances and behaviour are recorded. The new tokens are then claimable by qualifying addresses, often through a smart-contract claim interface. Some airdrops require active claiming with a small gas fee; others arrive automatically.
Example
The Uniswap airdrop in September 2020 distributed 400 UNI to every address that had ever traded on Uniswap before September 1, 2020. At peak UNI prices, that 400 UNI was worth over $14,000. Arbitrum’s airdrop in March 2023 distributed ARB tokens based on bridging, transaction count, and other criteria, with qualifying users receiving anywhere from 600 to over 10,000 ARB.
Why it matters
Airdrops have created some of the largest retail-to-trader windfalls in crypto. They are also a major attack surface: malicious airdrops trick recipients into approving wallet drains, and fake airdrop sites harvest seed phrases. Always claim through verified contract addresses, never sign transactions from unknown sources, and treat unsolicited tokens in your wallet as untrusted until proven otherwise.