The average number of payments per trip made by airline passengers is increasing as airlines debundle their product offerings in addition to steadily reducing the option of flying nonstop to a final destination. Some customers might buy a ticket with a corporate credit card, use a personal debit card to pay for excess luggage charges, and pay with a personal credit card for a seat upgrade. Handheld point-of-sale devices are used to accept card payments inflight from passengers who buy duty-free products and foodstuffs. Passengers pay over the counter for luggage service. Frequent flyers mig...