DQOTD: How are Dealers paid for service under warranty?

I may be the only human being who does not know, but how do dealers get paid for all routine and other warranty service they provide while a car is under warranty? The service that costs the owner nothing (out of pocket). I always assumed they got a fixed $ amount from Toyota (in this case) for routine services and there was probably a set $ amount for all other expected warranty repairs. I have heard that for many years now, many dealers make (much) more on service and even selling used cars than they do on selling new cars. Seems odd, but who knows.

My local dealer called me last night and while we were talking he mentioned 'you bought your TCH here in 07 and our records show that you've brought it here for all your service (all at no cost to us) which makes us even more interested in selling you another car.' So it made me wonder about how dealers get paid for warranty service again. He's only met me about 1/4 of the way to the discount I want (and don't expect yet), but I'm being patient.