Note to the haters--you know who you are--the "Brains" referred to are four professional economists.
Also there's this:
. . . led by Pat Bajari, Amazon has hired more than 150 Ph.D. economists in the past five years, making them the largest employer of tech economists. In fact, Amazon now has several times more full time economists than the largest academic economics department, and continues to grow at a rapid pace.
(That's Tyler Cowen, quoting a recent paper by Susan Athey and Michael Luca.)