In October 2005, JetBlue's quarterly profit had plunged from US$8.1 million to $2.7 million largely due to rising fuel costs. Operational issues, fuel prices, and low fares, JetBlue's hallmark, were bringing its financial performance down. In addition, with higher costs related to the airline's numerous amenities, JetBlue was becoming less competitive.
In April 2013, Frontier introduced a modified version of that livery, keeping the iconic animals on aircraft tails, but dropping its former slogan and replacing "FRONTIER" with "FLYFRONTIER.COM", the company's website, in support of new marketing that focused heavily on the airline's web presence. This livery was only painted on a few newly delivered aircraft. Aircraft in the older livery received "FLYFRONTIER.COM" titles on engine nacelles.
On July 1, 2010 Allegiant returned to Long Beach Airport (LGB) in Long Beach, California having previously served LGB with DC-9 jets with nonstop flights to Las Vegas (LAS) and Lake Tahoe (TVL) in 2000. The airline also intended to fly from Bellingham International Airport and Stockton several times a week; however, there is no service at present flown between these two cities although Allegiant continues to serve Stockton with flights to Las Vegas, Phoenix/Mesa and San Diego. In November 2011, Allegiant closed its Long Beach facility and consolidated all Los Angeles area flights at Los Angeles International (LAX).
Animal concepts used in the livery extend into Frontier's marketing as well. Each animal has a specific name. Animal aircraft used in their radio and television commercials include Jack the rabbit, Grizwald the bear, Foxy the fox (for whom Jack has a crush), Flip the dolphin (who always gets stuck going to Chicago rather than the warmer climates the others are going to), Larry the lynx, Hector the sea otter, and Sal the cougar. New additions are Penguins Jim, Joe, Jay, and Gary, a barbershop-style quartet, singing the praises of EarlyReturns to an audience of Frontier's well-known characters from the "a whole different animal" campaign, Hector the otter, advertising Frontier's expanding service to Mexico, and Polly the Parrot, who won the new animal audition in 2012.
For many years, analysts had predicted that jetBlue's growth rate would become unsustainable. Despite this, the airline continued to add planes and routes to the fleet at a brisk pace. In addition in 2006, the IAM (International Association of Machinists) attempted to unionize JetBlue's "ramp service workers", in a move that was described by JetBlue's COO Dave Barger as "pretty hypocritical", as the IAM opposed jetBlue's creation when it was founded as New Air in 1998. The union organizing petition was dismissed by the National Mediation Board because fewer than 35 percent of eligible employees supported an election.
On August 4, 2008, the Associated Press reported that jetBlue would replace their recycled pillows and blankets with an "eco-friendly" pillow and blanket package that passengers would have to purchase for use. Each package will cost $7 and will include a $5 coupon from retailer Bed, Bath and Beyond. This decision is the latest in a series of moves designed to increase revenue. jetBlue told the Associated Press that it expects to collect $40 million from passengers selecting seats with extra legroom and $20 million from passengers paying $15 to check a second bag. As of September 8, 2008 JetBlue charges passengers $10–30 for an extended-leg-room seat depending on the length of the flight.
Allegiant Air (G4) is an American low-cost carrier that is headquartered in a suburb of Las Vegas. Founded in 1997, the airline does not use hubs, but has designated more than 10 focus cities. These include McCarran International Airport (LAS), Fort Lauderdale–Hollywood International Airport (FLL), Los Angeles International Airport (LAX) and Orlando Sanford International Airport (SFB). Although Allegiant flies into some major airports, many of its destinations are smaller cities or secondary airports that serve larger cities. In total, the airline serves about 105 domestic destinations in 41 states. The airline's fleet of 81 aircraft are each configured with a single Economy Class cabin.
In December 2006, jetBlue, as part of their RTP plan, removed a row of seats from their A320s to lighten the aircraft by 904 lb (410 kg) and reduce the cabin crew size from four to three (per FAA regulation requiring one flight attendant per 50 seats), thus offsetting the lost revenue from the removal of seats, and further lightening the aircraft, resulting in less fuel burned.
JetBlue Technology Ventures (JTV)  is a wholly owned subsidiary of JetBlue that was established in February 2016. JTV is the venture capital arm of JetBlue that invests in and partners with early-stage startups in the travel, hospitality, and transportation space. Its mission is to improve the end-to-end experience of travelers everywhere. As of November 2018, JTV has invested in 21 startups, including hybrid planes, machine learning algorithms, and ground transportation. Investments range in size from $250,000 to $1 million.
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.
On September 9, 2014, Frontier introduced an updated livery, as part of a rebranding that saw the spokesanimals' roles increase. The new livery reintroduced a green "FRONTIER" typeface to the fuselage, featuring the stylized "F" designed by Saul Bass for the original Frontier in 1978. Each aircraft features the name of the animal featured on its tail near the nose of the aircraft for easier identification. Currently about twenty five aircraft in the Frontier fleet feature the new livery.
In March 2011, Allegiant took over charter service to Wendover Airport for Peppermill Casinos, Inc. to shuttle customers to Peppermill's three casinos in West Wendover, Nevada; the Montego Bay Resort, the Rainbow Wendover and the Peppermill Wendover. Allegiant based one 150-seat, MD-80 series jet aircraft in Wendover and more than 20 employees, including maintenance, flight crews and stations personnel.
In March 2010, Allegiant purchased six used Boeing 757-200 jetliners as part of plans to begin flights to Hawaii, with deliveries from early 2010 to the fourth quarter of 2011. It gained the approval for type with the FAA in July 2011, and then worked with the FAA to obtain the appropriate ETOPS rating in order to be able to serve Hawaii. Allegiant no longer operates nonstop service to Honolulu from Las Vegas.