The Best Frequent Flyer Program Belongs To One Of The Best Budget Airlines

Smart travelers know that being a frequent flyer is a game changer. As a member of an airline's frequent flyer program, you'll earn "miles" or points that are redeemable for better seats, free trips or even a free trip for a friend.

And to really rack up rewards, it's best to stick with one airline. So which frequent flyer program is the best?

According to a recent poll from Airefarewatchdog, Southwest Airlines has the best frequent flyer program in the domestic market. And it's no wonder, because Southwest also happens to be one of America's most beloved budget airlines.

The key is in the program's flexibility, says George Hobica, founder of Airefarewatchdog and an air travel expert. He notes that the poll's results should be taken with a grain of salt, as they likely reflect opinions from a budget-conscious audience. But let's be real: Who isn't budget conscious when traveling? Here's why Southwest's frequent flyer program may have won out among dollar-savvy travelers:

You're rewarded with free flights... all the time.

On Southwest, frequent flyer rewards don't come in the form of seat upgrades. (The airline has no business or first class.) After earning 110,000 qualifying points or taking 100 qualifying flights in a calendar year, however, you WILL get a Companion Pass that allows a friend or family member to fly with you wherever you go. Of course, you can also get free flights for yourself.

You can travel the same distance with fewer points.

By and large, Hobica says, Southwest points will get you farther than other airline points or miles. Instead of sticking to rigid price categories like 25,000 miles per flight or 50,000 miles per flight, Southwest adjusts the price of its reward flights based on the price, in dollars, of the flight itself (along with a few other factors, of course).

And your miles (pretty much) never expire.

Unlike some other airline rewards, Southwest miles are good forever, as long as you earn new ones (aka take a flight, use your Southwest credit card, eat dinner at a participating restaurant, etc.) once every two years. Sounds more than easy.

... And if you're curious, here are percentage rankings of the other top frequent flyer programs from Airfarewatchdog's poll:

Southwest -- 32 percent

Delta -- 17 percent

American -- 14 percent

Alaska -- 11 percent

United -- 11 percent

JetBlue -- 8 percent

Hawaiian -- 4 percent

Allegiant -- 1 percent

Frontier -- 1 percent

Spirit -- 1 percent