Billing is why tarsnap was too unreliable for prod usage for me. You deposit funds with a credit card, a difficult-to-predict usage calculation occurs based on how many deduplicated blocks of new data and how many API calls you will use in the next few weeks and months, and then eventually, at an essentially random time, you get an email from tarsnap guessing you have about a week of funds left and warning that your data will be deleted a week after that happens. Then a human with admin backup credentials and the org’s credit card in hand must log into the tarsnap website to add funds, resetting the time bomb for another few weeks or months.

Tarsnap is technically impressive and was reliable software, but the billing system requires an unpredictable manual process requiring two credentials held separately in most orgs. Colin has told me in private email that customer deletion is a manual step not taken lightly, but I didn’t feel that one unscheduled manual process was fixed by epicycling on another one.

I migrated away several prod installs to pay more for predictable and automated billing. Even with usage billing that’s not easy to predict, the date of next intervention is printed on the back of the credit card. (Though really, it does cost less - the engineer time it takes to manually add funds costs significantly more than a picodollar.)