There have been numerous threads on this topic over the years, and no one has ever posted exactly what the large companies pay for miles.

In this thread, milesrus asserted that in 2001, Citibank paid AA $678 million for miles.

At one cent each, that would be 68 billion miles.

No matter how you slice it, that's an awful lot of money for miles that will eventually be redeemed for capacity-controlled award seats and upgrades.

Although some airline employees still don't understand the economics of mileage programs, it is clear that award seats are not always "free." AA, along with Citi and other partners are actually selling the award seats a mile at a time to millions of customers.