A new craze for virtual kittens is slowing down trade in one of the largest crypto-currencies.
CryptoKitties lets players buy and breed “crypto-pets” on Ethereum’s underlying blockchain network.
The game’s developers told the Bloomberg news agency that CryptoKitties was a “key step” to making blockchains more accessible.
But its popularity has underscored one of the technology’s biggest downsides: its lack of scalability.
Etherscan has reported a sixfold increase in pending transactions on Ethereum since the game’s release, by the Axiom Zen innovation studio, on 28 November.
“CryptoKitties has become so popular that it’s taking up a significant amount of available space for transactions on the Ethereum platform,” said Garrick Hileman, from the Cambridge Centre for Alternative Finance.
“Some people are concerned that a frivolous game is now going to be crowding out more serious, significant-seeming business uses.”
An estimated $4.5m (£3.35m) has been spent on the cartoon cats at the time of writing, according to Crypto Kitty Sales.