section_path: Terminology/Trailer and teaser
section_name: Trailer and teaser
paragraph_text: Trailer and teaser
  
  Trailers or previews are advertisements for films that will be shown in 1 to 3 months at a cinema. Back in the early days of cinema, with theaters that had only one or two screens, only certain trailers were shown for the films that were going to be shown there. Later, when theaters added more screens or new theaters were built with a lot of screens, all different trailers were shown even if they were not going to play that film in that theater. Film studios realized that the more trailers that were shown (even if it was not going to be shown in that particular theater) the more patrons would go to a different theater to see the film when it came out. The term trailer comes from their having originally been shown at the end of a film program. 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 (or the "A film" in a double feature program) begins. Film trailers are also common on DVDs and Blu-ray Discs, as well as on the Internet and mobile devices. Trailers are created to be engaging and interesting for viewers. As a result, in the Internet era, viewers often seek out trailers to watch them. Of the ten billion videos watched online annually in 2008, film trailers ranked third, after news and user-created videos. A teaser is a much shorter preview or advertisement that lasts only 10 to 30 seconds. Teasers are used to get patrons excited about a film coming out in the next six to twelve months. Teasers may be produced even before the film production is completed.