Walk away. Very few ideas turn into a profitable business - the odds are strongly against you getting paid.

In my experience every product or feature finds traction with 1%-5% of users - indefinite retention, express strong satisfaction in surveys etc. For paid products the number is usually much lower. The questions you must answer are: 1. What's special about these people? Don't assume they are "techies" or "early adopters" - these answers are too generic and often wrong. You need to reach out to your best users and interview them. If you do enough of these a profile will start emerging - single parents living in suburbs, <50 person companies in the transportation sector ... 2. Why do they love it? What job is it doing for them? Once you have the answers to both you'd be in a good place to answer the question you're asking - is this a seed of a much larger market that's will grow significantly over the next few years.