Every "smart" business traveler I know chooses their flights based on FF programs. Many, myself included, have actually made their clients aware as to the airlines on which they prefer to fly. Let's face the facts: the business traveler, by paying last minute, exorbitant rates, basically subsidize the cheap seats in the back of the plane and the airlines are smart enough to realize this. Rewarding the frequent business traveler with a (no longer) free ticket on a plane, with seats which would probably, otherwise, go out empty is one of the most logical things I have seen any airline do.