A business model is usually presented as a diagram or a spreadsheet. Both make it look settled. In a new venture, very little of it is.
We treat the model as a set of bets. Someone will pay for this. They will pay this often. Serving them will cost less than they pay. Each line is an assumption until a customer proves it.
Writing the bets down makes them testable. Who pays: the user, their manager or someone else entirely? How often do they buy, and what makes them buy again? What does it take to deliver, support and keep each customer?
We then look for the cheapest way to test each one. A price on a landing page, a paid pilot, a manual version of the service run for a handful of customers. The goal is not certainty, but enough evidence to choose.
Some bets will fail. The model changes, and that is the point of testing it early. It is far easier to change who pays, or how, before the product, the brand and the team are built around the wrong answer.
A business beginning to grow rests on bets that have been tested. That is the business model part of getting to one.