Movie previews are called “trailers” because they originally came after the film.

In the early days of moviegoing, you didn’t just buy a ticket for one feature-length film and leave once the credits started rolling. You were instead treated to a mix of shorts, newsreels, cartoons, and, eventually, trailers — which, per their name, played after the movie rather than before — with people coming and going throughout the day. The idea for trailers came from Nils Granlund, who in addition to being a business manager for movie theaters worked as a producer on Broadway, which explains why the first trailer was actually for a play: 1913’s The Pleasure Seekers.

Chicago producer William Selig took the idea further that same year by ending each installment of his serialized action-adventure short films with a tantalizing preview of the next chapter — a precursor to ending movies and TV shows on a cliffhanger. Today there are production houses that exclusively make trailers and are handsomely rewarded for their efforts, sometimes to the tune of millions of dollars.