The phrase the BPH execs have used in public is "protecting the perceived value" of their product.
They dislike the idea that prevalent discounting might get consumers *used* to cheap prices and then start demanding them. Can't have that.
Better to pay $100 million or so to foster the image that each book is a priceless and rare jewel. Each and every one of the 3 million different books published last year. (To say nothing of the estimated 15 million coming this year.)
http://ptbertram.wordpress.com/2012/...e-for-a-shock/
Concepts like supply and demand and price elasticity don't factor into it.
It is all about maintaining the perception of value.
Less kindly, one might sale "propping up the illusion" of value.
But that might be redundant; popping illusions is the proper role of competitive markets.