American Airlines, the world’s largest carrier, said Tuesday that it is fundamentally changing the way it awards frequent flier miles, joining other major U.S. airlines by rewarding dollars spent instead of miles flown.

The change, also made by United Airlines earlier this year, benefits big-spending corporate travelers, who are more profitable for the airline, and hurts deal-seekers who take many cheap long-haul flights.

The change is also an outgrowth of how setting fares has changed. Years ago, fares correlated more closely with miles traveled, so miles were a good gauge of money spent with the airline. That’s no longer true. Flights of the same number of miles could cost $200 or $1,000, depending on a host of factors.

Industry experts said the change to a revenue-based rewards program seemed inevitable, and the changes to the program overall balanced the financial needs of the airline with the desires of its frequent fliers.

“There’s no way American could make these changes and make everyone happy,” said Henry Harteveldt, a travel industry analyst with Atmosphere Research Group.

American’s AAdvantage loyalty program changes, which begin in the second half of 2016, affect both accumulating reward miles and redeeming them, or “earn and burn.”

While the changes are not a strict copy-and-paste of its competitor’s programs, many features are similar.

On the earning side, regular AAdvantage program members get 5 miles for each dollar spent, while gold members get 7 miles, platinum get 8 and executive platinum get 11. Those earning levels are in line with competitors.

So a regular member whose fare and fees totaled $1,894 to fly round trip from Dallas to London would earn 9,470. That’s less than under the current system, in which the same flier would earn 9,502 miles because the flight is 9,502 miles round trip. Using the same example, a gold member would earn 12 percent more reward miles, while a platinum member would earn 20 percent fewer miles.

American is tinkering with what’s generally regarded as the best frequent flier program among major carriers.