Are you one of those who often wonder if those unused gift cards you'd received for holidays and birthdays could help you enjoy a dream vacation for less? If you don't already know, United Airlines rolled out a unique program completely unique to the airline industry that allows members to exchange unused gift cards for air miles 4 years ago. The program continues to be discovered by loyal customers looking to maximize their potential to fly cheaply. This arrangement does truly make it possible to turn cards that are unwanted, or unlikely to be used by you, into usable miles.

Known as United's MileagePlus Gift Card Exchange, this program was created specifically for the purpose of allowing members to convert used or partially used gift cards into usable, tangible miles. The program allows members to exchange cards from more than 60 retailers, including The Home Depot, Gap, Barnes & Noble, Sears and Target. Do note that this perk is only available to members of the airline's popular MileagePlus loyalty program.

How United's MileagePlus Gift Card Exchange Works

The process of converting gift cards into miles is pretty basic for MileagePlus members. Users simply to log on to the MileagePlus website, select the gift card retailer they're using and enter the information on the gift card.

United Airlines will verify the information on the card and automatically convert the balance into miles. Users will then have the new miles deposited into their accounts. The new balance should be displayed within five days.

United Airlines doesn't require members to physically mail in the gift cards, too. Members can simply discard gift cards once the balance has been applied to their accounts. It is also worth noting that paper gift cards of any kind won't be considered. United is only interested in plastic gift cards with clear account numbers.

Paying Attention Can Pay Dividends

Travelers can maximize the power of their unused gift cards if they pay attention to catch the special deals that are offered from United throughout the year. The airline occasionally offers bonus incentives that will increase the mileage awarded in exchange for gift cards by as much as 40 percent.

The Numbers Behind The Deal

It is important to note that there are rules when it comes to exchanging gift cards for miles. United only honors cards in increments of $25 or higher. The other thing that should be noted is that the mileage value of gift cards is not static. United actually increases and decreases the value of gift cards based on market conditions.

The exchange typically works out so that members receive three to four miles for every dollar they trade in. Participants can use the MileagePlus Gift Card Exchange portal to enter gift card amounts and see how many miles would be exchanged at any given time.

The bottom line is that users are definitely paying a bit of a premium when they work out the math on exchanging gift cards for miles. Nonetheless, users aren't technically losing money if they are using gift cards that were purchased for them by other people.

And if miles are going to be more useful to you than the gift cards themselves because you don't even shop at those merchants, we think you'd be better off cashing in your gift cards for miles that you can use to offset your travel costs.