American's AAdvantage program is one of the largest and most popular loyalty programs in the world.

Members can earn miles for flying on American Airlines and participant airlines as well as for transacting with over 1,000 participating companies, both travel and non-travel related.

And members can redeem miles for flights to almost 950 destinations worldwide as well as other awards including flight upgrades, vacation packages, car rentals, hotel stays and other retail products.

It's free and easy to join the AAdvantage program.