I would think because they offer some protection with this service, that it attracts more buyers.
I would be interested to hear from X33RS (Larry), or Jack92584 or anyone else, if you were interested in a car, and given that Jerry is on site how much time does he spend with each car? do they have a lift where he verifies drive train? or does he just check the tags, and hidden vin quickly and move on? (considering there are about 50-100 camaros there)