The point of marketing is that you don't necessarily know what a great product is. You might think you do, but that's not based on evidence (except if you have loads of experience in a market and industry, as in 5 years +). And even if you do manage through experience or sheer luck to put out a great product, selling / monetizing it through luck as well is unlikely.

What I like particularly here is how every feedback and game design element contribute to the fused goal of learning-playing. Textbook game design elegance!