United Continental

Swap unwanted gift cards for miles on United Continental

Even novice players of the airline mileage-program game know how to earn extra frequent flier miles through shopping, dining, hotel stays and car rentals.

Now there’s one more way to feather the free-trip nest: On Monday, United Continental Holdings launched the MileagePlus Gift Card Exchange, a program that allows members of United and Continental airlines’ MileagePlus program to swap unwanted gift cards from more than 60 major retailers for miles.

“The program enables members to get value out of gift cards that they normally wouldn’t use or didn’t want,” said United spokesperson Charles Hobart. The airline claims the program is the “first of its kind.”

To swap cards, MileagePlus members log into their accounts and enter the value and other information from an unwanted gift card. The site will verify the card, make an exchange offer in miles and, if the offer is accepted, “take” the card and, within about five days, deposit miles in a member’s account.

There are some restrictions: Cards with balances below $25 will not qualify, nor will cards that have expiration dates. And not all cards will be accepted or exchanged for face value. “Our rates are determined by market pricing, which is affected by several factors,” the program rules state. Those factors determining a card’s value aren’t fully spelled out and the rules note that the mileage offer displayed for the same gift may fluctuate over time.

“This looks like a modest win for MileagePlus members, who now have yet another option for using their miles,” said Tim Winship, publisher of FrequentFlier.com, a site about airline-mileage programs. “But without a set exchange rate when converting card balances into frequent flier miles, it’s impossible to assess the real value of such exchanges except on a case-by-case basis.”

Winship says that floating exchange rates will likely detract from the new feature’s popularity, as could the 7.5 percent federal excise tax he suspects will show up as a reduction in the number of miles members receive for any exchange.

“If the exchange rates are generous enough, the tax hit may not matter,” said Winship. “But for those drawn to the program for its convenience, it’s probably a non-issue” and will likely be a feature other airlines and hotels may soon add to their programs.

(Note: an earlier version of this story appeared on msnbc.com Travel’s Overhead Bin)