Burger King is a real life fast-food chain that was founded in 1954.
Burger King and McDonald's are not present in Springfield as a result of a deal between Krusty and Fat Tony, whose mob keeps the Fast Food franchises out of the town while letting Krusty monopolize the fast food market in Springfield with his fast food chain, Krusty Burger.
Burger King had featured characters from The Simpsons in some of their advertisements. Several Burger King advertisements were aired to promote the release of The Simpsons Movie.
Prior to the release of The Simpsons Movie, Burger King launched the site "Simpsonize Me" where people can transform their photographs into characters in the Simpsons universe.
Over the years Burger King had several promotions with The Simpsons. Like in 1990 there was camping figurines for kids meals. In 2001 there was a Simpsons creepy classic's kids meal that was offered during Halloween. In 2002 there were 4 Simpsons talking watches, the Krusty one said: hey hey kids its story time!, the Homer one said: MMM burger, the family in the car one said: are we there yet? NO! (3 times), & the Bart one said: cool your jets man. In 2008 there was a promotion where there were couches with the family you connect together.