…depends on the shape of the cup.
Seattle Seahawks fans have discovered, to their chagrin, that the “large” beer sold at Qwest stadium contains the same amount of beer as the “small” beer, though it costs $1.25 more. See it for yourself on this YouTube clip.
Maybe all Seahawks fans were smart enough to see past this trickery. But the technique underscores how easy it is to inveigle customers just by shifting their frames of reference. (After the video circulated on YouTube, the concessionnaire at Qwest stadium said it would change cups.)
Thanks again to the Nudge blog.