Unused Frequent-Flier Miles 'Hidden Treasure' for Passengers

April 10, 2013— -- Two-thirds of Americans collect reward miles and points for travel, but the vast majority of us don't know how many we have. And even worse is that more than 25 percent of us are letting frequent-flier miles expire.

Your lost miles are a win for the airlines, said Brian Kelly, world traveler and founder of ThePointsGuy.com, the web site that conducted the research. "It's in the financial interest of the airlines for you to let your miles expire. They make money when you don't maximize miles."

Outstanding miles are a liability to the airlines, Kelly said. "All those miles have to be accounted for," he said. "That can affect their quarterly results."

Delta recently changed its SkyMiles program. Now, when a person dies, their miles die with them. They're the first airline to do so.

The airline also said earlier this year it would require a spending minimum in addition to distance flown to earn miles, making it harder for travelers on a budget to accumulate miles in the first place.

Kelly just returned from Brazil. He flew first-class and paid $2.50 for his ticket. Safe to say he keeps track of all his points.

But he flies 150,000 miles a year. Most travelers don't fly anywhere near that much. Most don't even fly enough in a year to rack up enough miles for a free flight.

It's those people, Kelly said, who are leaving "orphaned miles all over the place." But he said you don't necessarily need to be a frequent flier to earn miles.

"If you're going to shop at Walmart anyway," he said, "why not go through the airline portal to earns miles for your purchases?"

Members of Delta's SkyMiles, for example, can go to skymilesshopping.com and earn a mile for every dollar they spend at Walmart. Lesser-known brands offer up to 4 miles for every dollar spent.

"Travelers are sitting on hidden treasure. You need to treat your miles like money," Kelly said. "Even if you only have 4,000 miles, use it to buy magazines, something."

He acknowledges that it can be difficult to keep track of miles and points and recommends travelers keep all their information in one place. He uses AwardWallet.com and Tripit. Tripit, he said, will send an email when miles are getting close to their expiration date.

And because travelers love to hate the airlines, isn't the best revenge to use their own programs to your advantage? Kelly thinks so.

"It takes a little time to figure out," he said. "but once they're all in one place, it doesn't have to be a full-time job."

After all, he said, "Having your head in the sand is exactly what they want."