Like many of us, we're idea factories. I've definitely built a few things that I thought were really cool that went nowhere because ultimately it was really only something I thought was neat. Unfortunately, I thought I was too clever and failed to evaluate wether it stood a chance at commercial viability. People would just be like "wow, I didn't know I needed that, but I do!". Haha, not how it works in reality. Live and learn (again).
So, here's a simple matrix from my personal toolset that I've been using to figure out how difficult my baseline idea will be to find a dedicated audience. I hope it helps you.
As some of you know, I'm working on a small team/startup project management software called Mission (missn.com). Based on this matrix, I really think this class of software is helpful, but not essential. How helpful it is has a strong correlation with the number of people on the team or jobs to do. With this understanding I know that my audience is a much smaller subsection of small startup teams and will likely get abandoned as the team grows. So, I need to focus on solving these problems, designing need-to-have features for the smaller teams and then focus on scalability.
Keep crankin', team. We'll get there.