$BTC One of the well-known cases of conducting an airdrop was the action of the company Omise, which in September 2017 distributed five percent of its cryptocurrency OmiseGO to Ethereum holders[1]. Airdrops are conducted to attract attention to new cryptocurrencies and projects, as well as to increase the number of users and distribute coins among a larger number of people.

1. ru.wikipedia.org: Airdrop (cryptocurrency)