If you were ask the average American to invest in the U.S. Postal Service, you would get a puzzled response. After all, the USPS lost $15.9 billion last year. But consider the outcome of the highly anticipated initial public offering of the Royal Mail in the U.K., where investors were so hungry for shares of the 360-year-old postal service that the stock price rose 38 percent on the first day, Bloomberg BusinessWeek reports.