Any dealership that I ever worked in that was any kind of major player in the market had a small stock of some common application equipment for primarily the service customers that had a piece of equipment that just wasnt worth fixing anymore and they needed a quick replacement and wanted to purchase right away.

As far as rentals it's smart to have a substantial rental fleet of modern up to date equipment. So when a customer rents one of them they can see the product and get a feel for it. This is a great tool for selling equipment also.