alt Hacker NewsThese shouldn't even exist without a negotiated contract.
I can subscribe to your service for a specific fee on a monthly basis ($20/month say), and take the risk of losing that month's fee if your service or I make mistakes, or I can choose to drop another $20 mid-month, or anything for convenience.
Saying that the computer will "control" the billing and can run haywire tells me that I don't want to be anywhere near your pile of bad incentives.
Monthly electricity bills are based on usage, and it works well but there’s a limit to how surprising a bill can be. The difference is the relative orders of magnitude you can be charged for these services you can go from 20$/month to 200k/month without warning.