Usage-Based Pricing
Usage-based pricing charges customers in proportion to how much they actually use the product, by API call, gigabyte, message, seat, or transaction, rather than a flat subscription fee. The customer's bill rises and falls with their consumption, so price scales with the value they're getting. It's increasingly the default for infrastructure and AI products where consumption varies hugely between accounts.
For a founder this model has two big attractions. First, it lowers the barrier to start: customers pay little when they're small, so adoption is easier. Second, it builds expansion revenue automatically, because as a customer grows, their bill grows with them, no renegotiation needed. The cost is predictability, both for you and the customer, who may dislike a bill they can't forecast. Many products land on a hybrid: a base subscription for predictability plus usage on top for upside. The key is that your unit of pricing tracks the value the customer perceives.