The Simpsons -- Bart, Homer, Marge, Lisa,and Baby Maggie -- have always been popular, but not so popular as the folks at the United States Postal Service thought they were. According to Bloomberg News, the USPS spent $1.2 million in 2009 and 2010 to print 1 billion stamps commemorating the show's 20th anniversary. With an average audience of 3.5 million, that's nearly 300 stamps per viewer. Needless to say, sales failed to reach the projected number, and the result is that the postal service now has 682 million unsold Simpsons stamps on its hands -- few of which are likely to be sold since they bear the old 44-cent postal rate. Bloomberg pointed out that, according to a report from the inspector general, the USPS overproduced 2.1 billion commemorative stamps in 2009 and 2010.