>Delta Air Lines earned $8.2 billion from American Express in 2025, surpassing ticket sales revenue.

Just to be clear, that isn't what the article says. It says more than what "most" airlines generate in ticket sales. Not Delta, or any major US carrier. As interesting as that sounds, it couldn't logically make sense and it only represents about 15% of Delta's revenue. It's not even a straightforward revenue stream, it works for profitability because they are able to book most of the revenue immediately and able to mark down the future expense because of how loyalty rewards are obligated.