You must know your market if you are to be successful, so spend a great deal of time analyzing just who it is that will want your product, and how you plan on appealing to them to take cash out of their bank account and give it to you.
What is the size of your market, will there be opportunities to expand the initial market, and what are your sales potentials?
When you understand these variables, you want to sell them to the person reading your business plan.