So if you can put this all together, you can have a complete business operating plan that would show you exactly what your business would need to do to give you the income and profit you would like to have and a rough idea whether your market would support it or not. All you would have left to do would be to figure out how to make it all happen. It's like planning backwards. 1. Determine what you want in life 2. Figure out what your business would need to do to give you that life. 3. Figure out how long it would take you to reach it. 4. Figure out how big of a market it would take each of the years you're planning for. 5. Then see if that market is big enough.
Is there enough demand for your product or service? This is something you'll want to investigate in more detail as you develop your business plan. At this point though, what's important is to do some preliminary research. Searches on Google, Hoovers or Bizminer will help you study a particular industry, and you can often drill down your research to a particular state or city. Your search at Google is of course, free, but you'll often find for a small investment at sites such as Hoovers or Bizminer, you'll get meaningful data for your market vertical, which you can start analyzing right away. It's also not a bad idea to survey buyers on their purchase behaviors and perceptions towards your product or service. Arranging a questionnaire or focus group can give you some useful insight into how potential buyers react to your product or service. If it's reasonable, consider giving away product or service trials and then follow_up to evaluate user expectations and experiences. If you don't have demand for your product or service, it really doesn't matter how great it is anyways, right?