Pets.com

Pets.com sold pet food and supplies online, with Amazon as a shareholder. Its mascot, a sock puppet with a microphone, got its own interviews, a balloon in the Macy's Thanksgiving parade and a Super Bowl commercial in January 2000. The company went public the following month.

The problem was not that nobody wanted to buy dog food online. It was that heavy bags were shipped at a cost that often exceeded the price, so every order lost money and more orders lost more. In November 2000, less than a year after the IPO, the business was wound down. PetSmart bought the domain, and an auto-loan company bought the sock puppet for its own ads.