In the last few months, carriers like UAL Corp.'s United Airlines, AMR Corp.'s American Airlines and US Airways Group have said they will look at the pros and cons of spinning off their frequent-flier programs into a separate company.
 

Analysts and investors have been pushing such separations because they say the cash-generating businesses would garner a richer value in the stock market if viewed apart from the business of flying people. Many say they are worth more than the carrier's themselves, though there are several hurdles to such spin-offs.

If any airlines do float their frequent-flier programs, passengers should prepare for some changes -- some good and some bad.

 
On the plus side, an independent mileage program is likely to increase the number of ways consumers can earn miles. That's because the plan gets revenue from selling the miles to partners such as airlines, retailers and credit card companies. These companies, in turn, use the miles as a marketing lure to get customers to pick their service over a rival's.

 
"Expect a lot more partners from a wide range of sectors (retail, dining, lifestyle, financial services) to be added to the program," said Alexander Meili, planning director for ICLP, a Zurich-based loyalty marketing agency.

 
A big uptick in miles sold, however, carries its own downside for the traveler that piles up miles. There could be more competition for already limited frequent-flier seats and class upgrades.
"Because you have so many partners, you'll be able to build up mileage account much quicker," said Randy Petersen, publisher and editor of Inside Flyer magazine. "It's good for the average consumer. But it's bad for the true frequent flier because they are now competing for benefits and free seats, not just with a few 1000 frequent fliers, but with hundreds of thousands of global citizens."
At the same time, independent plans are also likely to expand the number of ways mileage holders can use them, from booking hotel rooms to buying TVs.
But exchanging miles for other products has never really taken off, says SmarterTravel's Winship. Customers mostly value their miles for their ability to get them airborne.