It’s relatively easy to get upgraded on American Airlines flights if you’ve booked via an eligible method. There are four primary ways to secure an upgrade on an American Airlines flight: purchase an instant upgrade after booking with cash or miles, get a complimentary elite upgrade within North America within four days of departure, use…

Go back 12 years, and JetBlue was an airline known for its egalitarian experience: all-coach cabins, no long-haul flights, and few bells and whistles beyond its trademark seatback screens. Over the past decade, things have certainly changed. 2014 ushered in the airline’s lie-flat Mint cabin. Then came flights to Europe, and — most recently —…