Teams treat metering as plumbing you bolt on at the end. That's backwards. **How you measure usage is a product decision**, and it quietly shapes everything from architecture to customer trust.
The unit of value is a design choice
Do you charge per seat, per request, per GB, per outcome? Each answer pulls the product in a different direction and teaches customers a different mental model. Get the unit wrong and no pricing page will save you.
Draft — to finish
*(Outline: metering as the contract between you and the customer; why usage-based billing is a distributed-systems problem; the reconciliation nightmare and how to avoid it.)*