Passengers on a Boeing 737 Max-8 plane during a United Airlines flight departing from Newark Liberty International Airport (EWR) in Newark, New Jersey, US, on Wednesday, March 13, 2024.Bing Guan | Bloomberg | Getty ImagesNow playing on United Airlines' seat-back screens: personalized ads.The carrier on Friday said it launched a media platform to serve travelers personalized advertisements on seat-back screens and in its app, among other platforms, as it seeks to leverage customer data.United sai...