This post mentions loyalty programs for frequent flyers, but it completely underestimates their importance. The difference between business class and coach is

This post mentions loyalty programs for frequent flyers, but it completely underestimates their importance. The difference between business class and coach is so stark, just a reasonable chance at an upgrade completely decommoditizes the inventory. Because of this, the most profitable customers certainly aren't basing their decisions solely on price. Myself, I always fly American, not because the coach experience is any better but because I've got about a one-in-four chance of getting upgraded to business class. Just a couple of days ago I got upgraded on my redeye back from SFO - well worth the $35 or so extra I paid for the seat vs. the equivalent flight on a competing airline. Slept like a baby, and I certainly couldn't have done that back in steerage.