Amazon's EC2 hourly prices are rounded to mils ($0.011/hour).

https://aws.amazon.com/emr/pricing/

Azure has some hourly prices with ten-thousandths of a cent ($0.0102/hour):

https://azure.microsoft.com/en-ca/pricing/details/virtual-ma...

Microsoft should use gas station 9/10 pricing conventions to just barely undercut Amazon's lowest price $0.011 with $0.0109.

https://www.marketplace.org/2018/10/11/why-do-gas-prices-end...

>“They found out that if you priced your gas 1/10 of a cent below a break point, let’s say 40 cents a gallon, ‘.399’ just looked to the public like 39 cents…”

Tarsnap goes as low as counting attodollars. Yes, that's 10^-18 dollars, judging by the precision with which individual line items and total account funds are reported. Storage price is 250 picodollars per byte-month.

If it’s not possible to charge such amounts, what exactly is the point of the accuracy?

They're usually charging you for a shitload of them!

Tarsnap is prepaid.

"Tarsnap's author is a geek." ;)

https://www.tarsnap.com/picoUSD-why.html

"when it internally converts storage prices from picodollars per month to attodollars per day, it rounds the prices down to benefit the customer."

A gentleman and a scholar.