... which is part of the point of this simplistic method : You're quickly able to pick the brains of all your (future, potential) competitors, without even know

... which is part of the point of this simplistic method : You're quickly able to pick the brains of all your (future, potential) competitors, without even knowing who they are, or researching what they're selling. Maybe you can envision a higher-priced product with the same purchase rate (a win), or a lower-priced product with a vastly better purchase rate (also a win). But, using the assumption that there are people already trying to optimize their offerings in the market-place, the back-of-the-envelope calculation from the article is a quick sanity check.