My colleague Perry was clutching a Ben & Jerry’s ice-cream bar. Our office, which made websites at the turn of the millennium, had decided to try Kozmo.com, a new site that promised to bring DVDs, books, and treats to your door within an hour. We paid a couple of dollars for the ice-cream bar—delivery was free. Yet Perry’s eyes opened wide, the way they did when something bad was about to happen. Kozmo.com collapsed a year later, in April 2001, along with much of the rest of the dot-com economy