Hmmm, no, I don't think I've ever seen an RV service shop that does that. Don't think its necessarily a bad policy, either, depending on the specifics of it.
By 'specifics', I mean this: Is their labor rate and parts pricing for everyone that doesn't buy from them 10% higher than the typical market rate, and right at market rate for their customers? Or, is it 10% BELOW market rate for their customers, and right at the average rate for those that don't buy from them? Should be easy to tell by comparing their shop labor rates and parts prices to other dealers around the area.
Bottom line: If they charge 10% more than what others charge just 'cause I didn't buy from them, then I won't be giving them much business. OTOH, if they charge about the same as others, and discount it 10% for their customers...I'd have no problem with their policy and would give them business, if they are close and convenient. I might even one day buy an RV from them, and start enjoying that 10% discount. :)
As to constantly 'rubbing it in your face' about the 10% discount: My answer would be, "..Well, thats all fine and dandy, but if you keep rubbing that 10% discount in my face, you will lose 100% of my business, 'cause I'll go somewhere else." If enough people say that (and start doing it), I bet they'll knock that routine off. :)
