Chocolate Bar loyalty card.
The Chocolate Bar here in Manhattan (just reopened in the West Village, according to their website) calls itself the "candy store for grown-ups." I've never been, but have heard that it's heaven for chocoholics. Here (click image), via ad agency Grey NYC, is a tasty little piece of truth in advertising. Every purchase is recorded with a punched tooth. After 16 cavities, you get a free chocolate (image via).
previously in local promos: the NYC condom—Get Some! Ricola's ill-conceived million-dollar mystery cougher campaign. Museum of Sex bursts its blowjob balloons. I-banker boot camp—HOO-AH!!! The Target bus (boom). The NYC Office of Emergency Management thinks they're funny.