Originally Posted by GUWonder

Frequent flier programs may have an anti-competitive effect but that does not make the programs anti-competitive. In many regards they are the product of competition, for if one airline offers a better program than the other airline, the former gains at the latter's expense until the playing field is levelled again. These programs do give airlines some pricing-power (arguably an element of oligopoly/monopoloy power) but the barrier to entry of providing a frequent flier program or some other award program is not so high that I would classify it as anti-competitive.