Airdropping is a new term in the crypto world. It refers to the way that cryptocurrency developers chose to promote their new coins and encourage traders to adopt their cryptocurrencies. This is done by developers of newly-developed cryptocurrencies who drop new coins into users’ wallets already holding existing cryptocurrencies for free. For example, NEO holders received free cryptocurrency named Ontology a few weeks ago, Everipedia and smart-contract system United Bitcoin developers are also planning to use airdropping in the future.