The most basic business model question is: how will you make money?  Peeling the onion on that question, and it becomes more complicated than just choosing a pricing model.  What value will you deliver to each customer segment?  How will you deliver it?  Through what channel?  With what partners?  With what cost structure?  With what pricing? 

The Business Model Canvas provides a model to brainstorm and organize the different aspects of your business model.  And once you develop the model, you need to validate it.