CryptoKitties is a new blockchain-powered online game where users can buy and sell collectable virtual cats on a marketplace as well as breed new kittens. While a virtual cat collecting game may seem insignificant and somewhat silly, CryptoKitties is actually the first large-scale decentralized application on the Ethereum network — and a driving factor behind why CryptoKitties are considered valuable is the concept of 'digital scarcity'.