After making a codeshare agreement with Lufthansa that went into effect in 2010, jetBlue transitioned to the Sabre reservation system used by Lufthansa, enabling the airlines to sell tickets on each other's flights, transfer luggage and passengers between the two carriers, and combine frequent flyer programs,. By making use of JetBlue's North America routes as a feeder network, the agreement put Lufthansa in a position to operate quasi-hubs in New York–JFK and Boston Logan.
It prefers to use smaller/secondary airports where landing fees cost less, such as Orlando Sanford International Airport. At Phoenix-Mesa Gateway Airport, Allegiant is now the only carrier. However, since 2015, Allegiant has been growing at major airports, such as Cincinnati, Denver, Memphis, Los Angeles, Raleigh/Durham, Indianapolis, and San Antonio.
As part of its plan to stay competitive in reaction to the entry of Southwest Airlines into Denver, the company underwent a reorganization early in 2006. On April 3, 2006, Frontier created Frontier Airlines Holdings (FRNT), a holding company incorporated in Delaware to take advantage of favorable tax laws in that state. The corporate headquarters did not leave Colorado.
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.