Food is an amazing multi-sensory experience. Taste is the obvious payoff, but we also talk about it with our friends and watch food shows on TV. Even listening to food (imagine the sound of bacon frying) can make your mouth water!
Fast food plays on these effects. They make their burger sound perfect on that radio ad, and before you know it, you're in the car and on the way for your favorite burger/taco/pizza etc. Fast food in the United States really began as a concept when the popularity of automobiles took off in the 1920s. With the highway infrastructure expanding, more Americans took to the roads, and restaurant chains realized they basically had captive (and hungry) audiences motoring along these long ribbons of concrete.
Have you wondered about the names of some of your favorite fast food restaurants? Some are rather perfunctory, (Taco Bell, McDonald's) while others are head scratchers.