I have to use my corporate credit card to make airline/hotel purchases, but have a great deal of autonomy over which airline and hotel I choose. What incentive do I have to pick DL if I don't get the miles? I'm pretty sure there are a large number of other flyers in my shoes.
That's nice. Our travel department would never allow the employees to gouge the company like that. Fortunately I don't have to travel for work.