Why Airline Loyalty May No Longer Pay OffReward programs have been eroding over the last 10 years as airlines shift their devotion to cold, hard, calculable dollars.

Sorry, frequent fliers:Airlinesthat once expressed their appreciation for you with free upgrades and miles to spend on freebie flights have turned tepid on the relationship. Frequency, in fact, may be out of style, as airlines shift their devotion to cold, hard, calculable dollars.

Reward programs have been eroding over the last 10 years as airlines boosted mileage thresholds for the purchase of upgrades and flights. But in the past year, several companies took relatively radical steps by raising requirements for high status levels, reducing rewards and generally devaluing points.