Have founders successfully applied to YC with just an idea? A "hey I think this would be cool, here's some data with respect to the market but I don't have a pr

Have founders successfully applied to YC with just an idea? A "hey I think this would be cool, here's some data with respect to the market but I don't have a product"? If not, what would you need to see from an application with no product to be accepted into YC? If so, what was about that application that made you believe in them so much?