How airlines make money

Tickets are still most of Delta's money, split almost evenly between the main cabin and the premium seats. A seat in the back and a seat in the front cross the country together; the difference is space, comfort and flexibility, and some travelers, often companies paying for business trips, pay much more for it. In 2025 premium ticket money grew 7% while the main cabin fell 5%, and Delta's new planes come with more premium seats.

The rest comes from miles, from fuel sold by Delta's own refinery, and from bag fees, cargo, lounges and repairing other airlines' planes.

Every time a Delta cardholder buys groceries or gas, they earn SkyMiles, and American Express pays Delta for them: $8.2B in 2025. Delta expects those payments to grow to $10B a year over the next few years.

Not all of it is profit. Some pays for the seats members fly later on their miles: award trips came to $4.2B of revenue in 2025, about 12% of the miles Delta flew passengers, on about 35 million award tickets. Delta counts miles money in two places: award trips when members fly on their miles, and loyalty program revenue, $3.4B, for the use of its brand and for miles spent on things other than flights. Miles not yet used wait on its books.

Flying is a thin-margin business. Delta took in 21.26 cents for each seat it flew one mile in 2025 and spent 19.31 cents to fly it, with its planes 84% full. Much of that cost is paid whether the seats are full or not: the plane, the crew, the gate, nearly all the fuel. So a few more empty seats, or a jump in fuel prices, can wipe out the gap.

Fuel was 17% of Delta's costs at an average of $2.30 a gallon, and its price swings: from $3.22 in one month of 2023 to $2.20 in one month of 2025. Delta even owns a refinery near Philadelphia, which can process about 200,000 barrels a day of crude oil and supplies jet fuel to its planes in the Northeast.