For Cartier (and similar 'luxury' brands) it's not that they lose potential sales to people who buy knock-offs, but once everyone is wearing replica Cartier watches, then the value of the brand falls, as the rich-but-dim people will stop wasting money on an over-priced Cartier watch, and will instead move to some other over-priced brand who have been more careful with their trademarks.
Biting the hand that feeds IT
