Here is my initial take.
Idea is to have many of such business models sketched out. It helps keep all moving parts within context.
Download business model template from slideshare.net.
A startup is a search for a repeatable and scalable business model. As a founder you are testing a series of hypotheses about all the pieces of the business model: Who are the customers/users? What’s the distribution channel? How do we price and position the product? How do we create end user demand? Who are our partners? Where/how do we build the product? How do we finance the company, etc.