One of the most popular frequent flyer programs is Delta SkyMiles, the loyalty program of Delta Air Lines with more than 120 million members.
Joining the program is free, and your miles never expire. TPG values SkyMiles at 1.25 cents each in our most recent valuations from February 2026.
You can earn Delta SkyMiles through a variety of methods. Some popular options include flying with Delta and its partners, spending on Delta's cobranded cards, transferring points from American Express Membership Rewards, shopping through the Delta SkyMiles Shopping portal, dining through the Delta SkyMiles Dining program and taking advantage of various other promotions offered by the airline.
A great solo travel tip spotted this week on The Points Guy Articles.
