Interesting

From webmd.com

“Next time a salesman’s badgering you, here’s how to uncover his true intentions. First, understand that on a shelf of, say, five DVD players, the high-markup items will be displayed second from the left and second from the right at eye level; statistically, consumers don’t purchase from the edges or middle as often. If he’s pushing, ask, “Is this the one you’d buy?” Now watch his eyes: If his pupils grow larger, you’ve struck a nerve. His mood is changing. And you have your answer — it’s not the one he’d want.”