I will bite, despite suspecting that this is a useless argument to wade into :). What do you consider "valid quantities?"
I have heard of people on here living in silicon valley who claim to purchase occasional drinks with cryptocurrency, but I have not heard of practical or regular expenditures with cryptocurrency or anybody that I know offline who uses it for any kind of expense.
> CryptoKitties, the Ethereum-based digital kitten collectibles game, has processed more than $12 million in sales on its decentralized marketplace.
Source: https://cointelegraph.com/news/cryptokitties-sales-hit-12-mi...
Also, a story on their revenue model => https://medium.com/@codetractio/a-look-into-cryptokitties-re...