Delta Air Lines, one of the nation's largest carriers, is revamping its loyalty program to offer members reward miles based on how much money is spent instead of on the number of miles flown.
The points accumulated in the Delta's Skymiles program before the changes are set to start Jan. 1 will not be affected. Under the changes, members can earn between five and 11 miles per dollar spent, depending on the member's status level.
Southwest Airlines adopted similar changes to its Rapid Rewards program in 2011, a move that angered many longtime Southwest fliers.
The changes at Delta won't affect members who get points through the Skymiles credit cards.
Brian Karimzad, director of the credit card review website MileCards.com, said the big losers in the Delta change will be fliers who buy the cheapest fares to accumulate points toward future flights.
"This earning rate is a fundamental change, and a negative one for many fliers," he wrote.