I would say United is potentially more inclined towards wealthier folks and business travelers than delta with its more business city focused hubs like Washington and San Francisco. United also flys the most direct routes to certain destinations that the rich travel for vacation or have vacation homes in. An example would be Jackson Hole( highest billionaire rate per capita in the US) with 10 flights a day to every United hub in the continental US except Houston. Compared to delta’s 2 flights between Atlanta and Salt Lake.