It started out because a designer who sells fonts wanted to hire me to build a font previewer for their website so that customers could demo the fonts without being able to steal them. I quoted them the price and they said it was out of their price range. I said I would build it for free if they subscribed for a low monthly payment. They were ecstatic at the deal and invited their friends to sign up. Turned out it was an unsolved niche in the font design community. I posted it to a few websites where people were asking for a tool that does this. The rest is history.