On: How do you process credit cards?

The smaller the granularity the more likely it is you'd need some sweeping change at the top of the chain -- at the CC providers, banks, processors. Most services charge you for every authorization request you initiate, let alone successful or failed transactions, so you'd have to be charging a very high rate for your service to be authing a card once a minute.

Not only that, but that many authorization attempts would immediately trigger fraud filters and the account would be locked.