FWIW, I love the idea of a bootstrapped business serving a niche audience... I guess my main point is that there is a fork in the road for startups-- if you want to get funded, you are almost certainly NOT going the niche route. For investors to get excited, yoou need to start getting monomaniacal about attacking a huge opportunity and building a huge business. Investors need to hear a story that involves them getting a 10x return (or at least the potential of it) or they almost certainly aren't buyin'.
Either way-- grats on what you've built!