UBR - Unique Buying Reason - apologies USP!!

I happened to speak up with a friend of mine, a communications strategist! He challenged the ubiquitous USP theory that all of us in the communications business have sworn by... But, i guess what he said made eminent sense and rationale..... Why does a customer buy a Merc... is it for the engineering excellence and design perfection?? well.. advertisers who made the tagline and put billions behind the ad campaign would wish so, but if I had to buy Sunils' theory of UBR (Unique Buying Reason - it could be Rationale if i am allowed to rechristen it! ha ha!!), the reason the Merc got drove out of the showroom was the UBR - a status symbol or a Page 3 attraction.. the same can be extended across a host of products and services... whatever be it, there is no denying UBR a place it deserves it the communications strategy blue book... Thanks Sunil for provoking thoughts....... Agree, disagree, write.....