If you're only serving your neighborhood, you can expand to cover the entire city. If you're covering your local county, you can extend your services to surrounding counties, or even go statewide. It helps to know how many customers you'll need to be successful. You also need to analyze your market to determine things like market potential, market size, and market share. Market potential is how much potential demand is out there for your service.
Market size has to do with the current demand for our services.
And of course, market share is how much of that potential and current demand you can expect to capture. When you compare your estimated market share to your break-even figure, you should be able to tell if the risk of going into business is worth the potential rewards.