The Simpsons their advertising. As a promotion for "The Simpsons Movie", twelve 7-Eleven stores were transformed into Kwik-E-Marts and sold "The Simpsons" related products. These included "Buzz Cola", "Krusty-O" cereal, pink doughnuts with sprinkles, and "Squishees". In 2008 consumers around the world spent $750 million on merchandise related to "The Simpsons", with half of the amount originating from the United States. By 2009, 20th Century Fox had greatly increased merchandising efforts. On April 9, 2009, the United States Postal Service unveiled a series of five 44-cent stamps featuring Homer, Marge, Bart, Lisa and Maggie, to commemorate the show's twentieth anniversary. "The Simpsons"
The Simpsons storylines in favor of and overuse of celebrity cameo appearances and references to popular culture. Schembri wrote: "The central tragedy of "The Simpsons" is that it has gone from commanding attention to merely being attention-seeking. It began by proving that cartoon characters don't have to be caricatures; they can be invested with real emotions. Now the show has in essence fermented into a limp parody of itself. Memorable story arcs have been sacrificed for the sake of celebrity walk-ons and punchline-hungry dialogue." In 2010, the BBC noted "the common consensus is that "The Simpsons" golden era ended after season nine",