Buying or leasing: What is better for the car dealership?

I would like to learn something about the motivation of my car dealership (with which I am very satisfied). The question is: what does my car dealership deserve most? Repairs and inspections occur on all three models with normal course to the same extent. With my current vehicle I am extremely free and with all the discussions I am not quite so sure on what I enter with a new vehicle. At present I prefer economic criteria for my decision. Who can give more detailed information? Hasel