Collectors of the digital cartoon cats are clogging up the ethereum network, delaying transactions, and causing a pile-up of unprocessed transactions.
The collectors are playing CryptoKitties, a game built on the ethereum blockchain where players spend ether—the digital token used by ethereum—to breed cartoon kittens or trade with other players. Unprocessed ethereum transactions have risen about six-fold since CryptoKitties was released on Nov. 28.
According to qz.com, CryptoKitties has the busiest address on the ethereum network, accounting for nearly 12% of all transactions. That’s a threefold increase from Saturday when it was responsible for about 4% of all ethereum transactions.
The value of the digital felines has skyrocketed. The most expensive kitten was about $5,000 when Quartz published a story on the phenomenon on Saturday. That same day, a kitten was sold for over $117,000. Dozens of kittens have been sold in the five-figure range, according to data provider Crypto Kitty Sales.
The network congestion forced the game’s developers, a Vancouver company called Axiom Zen, to raise prices. This made processing the game’s transactions more attractive to ethereum miners, improving the odds of the transactions being accepted. Some $2.7 million has changed hands on the CryptoKitties marketplace in the six days it has been active, according to data from Crypto Kitty Sales.