An anonymous reader shares a report: Does your wallet contain an airline-branded credit card? If so, your daily Starbucks visits, iTunes selections and dining habits serve a critical role in keeping the U.S. airline industry fat and happy. For carriers such as American Airlines, riding Citigroup Inc. plastic, or Delta, on American Express Co., these programs are a cash cow, a golden goose -- or any other fiscal livestock you care to conjure. Each mile fetches an airline anywhere from 1.5 cents to 2.5 cents, and the big banks amass those miles by the billions (alternative source), doling them out to cardholders each month. For the banks, people who pay annual fees for those cards in order to accumulate miles are the closest thing to a sure bet. These consumers typically have higher-than-average incomes and spend more on their cards, generating merchant fees for the banks. They also tend to maintain high credit scores, which means they pay their bills on time and banks experience fewer defaults. The airline-miles business, formally known as loyalty programs, has become a high-margin enterprise that's grown in size and value amid airline consolidation, with carriers keen to expand credit card rolls and see loyalty members spend more.