I'm inclined to disagree with the author's thesis. I agree that talking to users is essential, but I think his heurstic is arbitrary: "You’re doing it right if you can get a third of potential users to pay you money within a month of initial contact."

The real number you should be targeting is the number of users you need to pay in order to build a sustainable business, that could be above 80%, it could be below 5%, it could be 0 . . .

This is something that varies widely by business and I don't think it's good advice for a company that falls outside the scope I imagine the author is thinking of.