I don't disagree that's the case when a producer sells at a single price. Their revenue is the the rectangle formed under the demand curve[1] bounded by price *

I don't disagree that's the case when a producer sells at a single price. Their revenue is the the rectangle formed under the demand curve[1] bounded by price * quantity. What I'm saying is that having a single price means that consumer surplus is left on the table and that charging each consumer exactly what they'll pay for the good will capture that surplus. It will essentially "fill in" the space not captured by the revenue rectangle. In microeconomics this is called first-degree or perfect price discrimination[2]. 1. http://www2.harpercollege.edu/mhealy/ecogif/s&d/fig17-6.5.gif http://www2.harpercollege.edu/mhealy/ecogif/s&d/fig17-6.5.gi... 2. https://clas.ucdenver.edu/brian-duncan/sites/default/files/attached-files/econ2022-powerpoint16.pdf https://clas.ucdenver.edu/brian-duncan/sites/default/files/a...