A trailer (also known as a preview, coming attraction or attraction video) is a commercial advertisement, originally for a feature film that is going to be exhibited in the future at a movie theater/cinema. It is a product of creative and technical work.
Movie trailers have now become popular on DVDs and Blu-ray discs, 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 been adopted as a promotional tool for television shows, video games, books, and theatrical events/concerts.
The first trailer shown in an American 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. As reported in a wire service story carried by the Lincoln, Nebraska Daily Star, the practice which Loew adopted was described 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.
Due to trailers initially being shown after, or "trailing", the feature film, the term "trailer" was used to describe the promotion; despite it coming before, or "previewing", the film it was promoting. This practice was found to be somewhat ineffective, often ignored by audiences who left immediately after the film. Later, exhibitors changed their practice so that trailers were only one part of the film program, which included cartoon shorts, newsreels, and serial adventure episodes.