Frequent flyer programs: The most profitable part of the airline industry

Buying this week’s groceries or paying for a full tank of gas with a credit card might contribute more to the profits of the airline industry than buying a one-way ticket. That’s because frequent flyer programs have become a crucial part of the airline industry’s profitability. And that’s due to the billions of dollars banks and credit card issuers pay to buy bulk miles from airlines to reward and entice cardholders to make purchases with their cards.