Sometimes an idea is so simple and perfect, you wonder how no one thought of it before. Today's case in point—the bad-breath flipbook. JWT in Hong Kong created a bunch of them for Listerine, showing an attractive woman who appears to be speaking as you flip the pages. But before long, the smell of onions comes wafting toward you. At the end of the flipbook was a coupon for Listerine. The brand saw a staggering 66 percent redemption rate, according to the case-study video below. My suggestion for a follow-up: Go to summer festivals and give out free fans that smell like gorgonzola cheese.