Trailers are important marketing tools for films that are shown in theaters, on television, and online. They are shorter versions of films that inform audiences about the genre and plot. The goal is to generate interest and encourage people to see the film. Trailers are designed to complement film posters and target the same intended audience. They highlight a film's unique selling point to distinguish it from other films and help fill theater seats. The timing of trailer campaigns is critical to build excitement but not be so early that audiences forget about the film.