Drive 100 miles (160 kilometers) and walk into a grocery store you've never even heard of, and I'll bet you can walk right to the milk. That's because it's almost always in a cooler at the back of the store.
Why position a staple at a most inconvenient location? This arrangement is a prime example of marketing science. You'll need to walk down aisles filled with lots of other tempting goods just to reach the milk. It's no wonder most of us enter the store to get one thing and leave with a $150 grocery receipt. And just think how this particular shopping strategy adds up over time. Americans in 2009 spent $11.2 billion on milk alone. Just think about all those other zeros we'd need to add, just to calculate the extras we picked up, too.