When you are thinking about the credit card side of things, a GAAP income statement does not really give you a complete picture. The credit card business generates a lot of high margin cash - like 85% margin. Most of the miles that are purchased will never get redeemed or will be devalued over time, so while it might be a liability on the books, the reality is that it's a liability that will never need to be paid and if it does, its non-cash since it uses infrastructure that is already in place. The other great thing about the cash generated by the credit card business is that it requires negligible incremental overhead and COGS to operate it. The lounges are opened and the planes keep flying, regardless of whether the credit card revenue is there or not.

In the best of times, an airline might do slightly better than breakeven. Delta has basically been breaking even recently by flying airplanes. All their net income is from AmEx.