Building and delivering on a product is important. But a significant portion of your business model can be based around consulting work. Open source software is a good example, the software is free, but support, implementation and other work is often paid work.
- Will customers want to pay for training?
- Will implementing the solution for a customer be complex? Would they pay for an implementation project?
- Will you charge customers for support? Will there be support calls, tickets, etc?
- Are you expecting enhancement requests? What about paid enhancements to the product or solution you built?