Feedback. If you have a great feedback tool, your market will grow. We at Saleszip got most of our initial clients from a market place. Ranking system also helps.
We are working on it from January Last year. Both of us were working in the business development. We decided to take few clients externally. After working with them for six month we had saved enough. Both of us resigned from our jobs. Employers were fortune 50 companies. They were not too bothered. As company we are at place where we can choose the path we would like to take.
Advice : Find people who are in need of your services and ready to pay. Also check with your lawyer to avoid legal issues.