In 2013, Allegiant acquired nine Airbus A320-200 aircraft from Spanish flag carrier Iberia. Seven of the A320s were delivered in 2013 and were used for growth into new markets, including destinations in Mexico and the Rocky Mountains, as well as airfields such as Charlottesville and Shenandoah Valley in Virginia and Trenton, New Jersey. On February 24, 2015, Allegiant announced the purchase of 2 additional A320s from Philippine Airlines which entered into service in 2015. Later in 2015, the airline announced a firm order for an Airbus A320 direct from Airbus, the first time it has purchased new aircraft from the supplier.
In July 2007, the airline partnered with 20th Century Fox's film The Simpsons Movie to become the "Official Airline of Springfield". In addition a contest was held in which the grand prize would be a trip on JetBlue to Los Angeles to attend the premiere of the film. The airline's website was also redecorated with characters and their favorite jetBlue destinations and the company was taken over by the show/film's businessman villain Montgomery Burns.
Frontier Miles is the frequent-flyer program for Frontier Airlines, replacing the EarlyReturns program, which existed from 2003 to 2018. Frontier Miles can be earned by flying Frontier Airlines, using the Frontier Airlines World MasterCard, or by spending at partner hotels, car rental chains, cruises, and merchants. Frontier Miles can be redeemed for flights, magazine subscriptions, and car rentals. Since February 2019, hotel stays are also part of the redemption options.
The initial JetExpress partnership with Mesa ended in January 2004, when Horizon Air was selected to operate the routes. Horizon utilized slightly larger CRJ-700 regional jet aircraft on these routes. In August 2006, Frontier and Horizon ended their partnership. While Frontier was generally pleased with Horizon's operation, the carrier decided that it needed to revisit the agreement and find a provider with additional regional jets to grow the operation. The last of the CRJ-700's was returned to the Horizon Air fleet on November 30, 2007.