Airdrop is the practice of distributing tokens, usually for free, to a defined set of wallet addresses — typically users who interacted with a protocol before its token launch, or holders of a specific NFT, or sometimes simply random addresses meeting eligibility criteria. The two largest were Uniswap (September 2020, $UNI to ~250,000 addresses at $0.42 launch price; ATH near $45 made early claims worth over $150,000) and Arbitrum (March 2023, $ARB to ~625,000 addresses).
Why airdrops happen
Three reasons protocols airdrop:
Distribute tokens broadly to bootstrap decentralization. The Uniswap airdrop turned regulator and tax-authority attention to airdrops, but it was a clean execution: tokens to actual users of the protocol, no claim friction, no presale, no insider allocation overhead.
Reward "loyal" users. Most modern airdrops target users with on-chain history at the protocol — depositors, traders, voters, NFT holders. The economic theory: align tokenholders with users.
Market the protocol. Airdrops generate Twitter buzz, attract speculative users, and create a press cycle. The cynical version of every airdrop is "free marketing budget paid in tokens." The user has to evaluate whether the marketing benefits the protocol's long-term value.
The IRS treatment for US holders
Airdrops are taxable income at fair market value on the date of receipt, per IRS Rev. Rul. 2019-24. The tokens become a cost-basis asset; any subsequent sale or swap is a separate capital gains/losses event.
This is the surprise that catches many US holders: claiming a $5,000 airdrop on December 28, 2024 (when token price was $10/each), holding through a crash, and finally selling at $0.50 in March 2025 produces a $5,000 income tax bill plus a $4,500 long-term capital loss. Net tax outcome can be substantially negative; the loss helps but does not fully offset the income.
For valuable airdrops, plan the claim timing if possible. Some protocols allow claims over an extended window — claiming at a lower price point can reduce the income tax burden.
Airdrop phishing
The single most common attack vector tied to airdrops is fake airdrop claim pages. The attacker sets up a clone of the legitimate claim site, gets a high search-engine ranking via paid ads, and prompts a "claim" action that is actually a setApprovalForAll signature. The user signs, expecting tokens; the attacker drains the wallet.
Defense: visit the official protocol website only from a bookmark or the verified Twitter link. Never from a Google ad result, Telegram DM, or Discord announcement message. Verify the official URL on multiple independent sources before connecting your wallet.
Airdrop farming
The practice of strategically interacting with protocols that have not yet launched tokens, in the hope of qualifying for the eventual airdrop. Common targets in 2025-2026: zkSync, LayerZero, Linea, Scroll, Berachain, MegaETH, and dozens of other unlaunched chains.
Farming is rational economically — Arbitrum airdrops paid thousands per qualified address — but consumes substantial capital in transaction fees and time. For most US-resident holders, the expected return on airdrop farming has dropped sharply since 2023 as protocols tighten Sybil-detection criteria. Approach as a hobby with capped downside, not an investment strategy.
Further reading: Phishing, setApprovalForAll.