Aftermarket business is goldenLike every car manufacturer, the highest margins are in aftermarket sales and service. Parts and service keep the "engine" running so to speak.
People may neglect routine maintenance on a car until a problem arises and generally it's ok. But, this is not possible in aviation where service and safety is a must. If I could afford a private jet I know where I would be taking it for regular service and gladly paying the premium for it too. When it comes to flight, who is going to cut a corner to save a few bucks?