The genius behind creating things too impractical to buy

Do you really need another iPhone? Not really, but there's going to be another one anyway. That's because companies, as neuroscientist David Eagleman put it, "need to figure out how to feel out the border of the possible." It's a remarkable way to get you to buy more, and it works across the purchasing spectrum from cars to phones to houses. David's latest book: The Runaway Species: How Human Creativity Remakes the World.