Perhaps you should start off your pitch with "Why no one actually uses X."

We have a similar problem in research, where we have to always demonstrate that what we do is novel. A technique that I have taken a liking to is to talk about all of the related work as soon as possible, so we can distinguish ourselves immediately. The difficulty with only distinguishing yourself at the end is that your audience has been bearing a "someone has already done this" grudge the whole time. It's difficult for them to let that go, no matter how good your answer is.

edit: I just looked at the page for your startup, and it wasn't immediately obvious to me that your site is a place to find classes out in the real world.