wichita.edu
…that their choices might bring. Unbundled services available a la carte are significant revenue producers for airlines that have proven essential to airlines bottom line profits. Only about 75 percent of airline industry revenues comes from fares, the other 25 percent comes from other sources like seat upgrades, baggage fees, reservation change fees and …
https://www.wichita.edu/about/wsunews-releases/2018/09-sept/HolidayAirTravel-09-10-18_release.php