Pricing: irrational and rational mixing it up under the curve

I found this article title You're Pricing it Wrong: Software Princing Demystified

Being who I am, I never thought beyond the Demand Curve:

The sweet point is where the intersection forms the largest rectangle. This rectangle represents the calculation of sales × price, and the biggest rectangle represents the biggest revenue.

 The rest of the article allowed me to think a bit less rationally and find a bit of relevance for marketing.