You're definately correct on the loss of parts sales and service business.  If I could count on the machine going back to work in an hour or two after I call for service, that would be worth something.  If I have to pay someone to drive out and tear it apart and not have what it takes to fix it, then pay them to drive back again after the part arrives two days later, the utility of hiring the service call has pretty well been degraded.  If I can call and say "I need this" and send someone on the way, or better yet, have enough confidence to just start driving toward the part, that has some utility.  If I get there and then have to go back to the phone and start looking for another source, well, I'd have been better off starting out by calling around.  If I have to buy ahead of time to insure I have what I need, why would I not buy from the lowest cost supplier rather then the "servicing" dealer?

This seems to upset some here, but it seems to me that many dealers make their own bed so to speak, then get all fussy when they  land in it.