Do You Like A Popcorn? 

When I was a teenager and young adult, many of the movies were shown at drive in theaters.  You paid admission and drove your car into a large parking lot equipped with speakers for each car.  All you had to do was find yourself a spot about 3 rows from the front and ease your car up to the post that held the wired-in speaker.  Lift the speaker off the post and hang in inside your car on the window glass.  Then, turn the volume knob clockwise till you could hear the movie. 

Most of the time, you would get to see two movies.  This was called a "double feature".  In between the movies, an intermission or break was held.  Efforts were made by the owner to get people to come up to the snack bar and buy hot dogs, chili pies, drinks, and...popcorn.  Watch the following short video of an advertisement played during the intermission period...