Airlines had to be U.S.-based and “have a publicly available rewards search calendar with availability from 15 days to eight months from the time of search,” according to NerdWallet.
The nine airline programs that fit the requirements were Alaska, American, Delta, Frontier, Hawaiian, JetBlue, Southwest, Spirit, and United.
Hotel brands had to have properties in most U.S. states and offer a loyalty program with a rewards search calendar available to the public. It was also required for…