I know companies that did the same thing, only they were not onto something big. Having customers pre-product is a good signal. I'm sure that the class of compa

I know companies that did the same thing, only they were not onto something big. Having customers pre-product is a good signal. I'm sure that the class of companies for which this happens have a much higher success rates than a typical startup. However, that's far from knowing you've hit something big. That's something you can only say in hindsight.