What was the breakthrough moment that made you believe your startup could truly succeed?

Reading the book "Inspired" by Marty Cagan and seeing our product checks every point a succesfull product should check. We are going to be launching very soon :)

Wow just mentioned this in another thread, but receiving a lot of signups for my preorder campaign. I was hoping for about 200 preorders but in a little over a week I received over 750. I was always very hopeful that I was building something that people could enjoy, but now I know for sure I’m at least on the right track.