I'm reminded of how tedious it is when people debate how small something has to be before it can be called a microservice... Maybe the language needs to focus on something besides size.

If you pre-pay, you're creating a debt which is destroyed when service is rendered. If you post-pay you're creating a debt when service is rendered that is destroyed when you pay. In both cases the logic of when and how you pay is decoupled from the thing you're paying for. You've got to ask how far you'll let the two accountings drift (sync monthly is a common choice).

My feeling for "micropayments" is that they happen as part of the same protocol which is providing service. There's just one accounting. Settlement schedule is determined by the nature of the service. Maybe it's page views or packets or gulps, but whatever it is it's imposed by circumstance. They're... situated payments?

And the other style is... decoupled payments?