A trailer (also known as a preview or coming attraction) is an advertisement or a commercial for a feature film that will be exhibited in the future at a cinema, the result of creative and technical work. The term "trailer" comes from their having originally been shown at the end of a feature film screening. That practice did not last long, because patrons tended to leave the theater after the films ended, but the name has stuck. Trailers are now shown before the film begins.
Movie trailers have now become popular on DVDs and Blu-rays, as well as on the Internet and mobile devices. Of some 10 billion videos watched online annually, film trailers rank third, after news and user-created video.
The trailer format has also been adopted as a promotional tool for television shows, video games, books, and theatrical events/concerts.
The first trailer shown in a U.S. film theater was in November 1913, when Nils Granlund, the advertising manager for the Marcus Loew theater chain, produced a short promotional film for the musical The Pleasure Seekers, opening at the Winter Garden Theatre on Broadway. Loew adopted the practice, which was reported in a wire service story carried by the Lincoln, Nebraska Daily Star, describing it as "an entirely new and unique stunt", and that "moving pictures of the rehearsals and other incidents connected with the production will be sent out in advance of the show, to be presented to the Loew’s picture houses and will take the place of much of the bill board advertising". Granlund was also first to introduce trailer material for an upcoming motion picture, using a slide technique to promote an upcoming film featuring Charlie Chaplin at Loew's Seventh Avenue Theatre in Harlem in 1914.
Trailers were initially shown after, or "trailing," the feature film and this led to their naming as "trailers." The practice was found to be somewhat ineffective, often ignored by audiences who left immediately after the feature. Later, exhibitors changed their practice and trailers were only one part of the film program which included cartoon shorts, newsreels and serial adventure episodes. Today, more elaborate trailers and commercial advertisements have replaced other forms of pre-feature entertainment and in major multiplex chains, about the first twenty minutes after the posted showtime is devoted to trailers.