Movie trailers (those previews before the main feature) are pretty amazing
. Almost since the invention of film the movie trailer has been the main way of getting the audience interested in seeing your film. Some are short (I can remember the very first preview for "Silverado" consisted of hoof beats and a horse jumping over the camera.maybe one minute tops) and some are long (the preview for "The Godfather Part III" ran so long, and included so many credits, that people thought they were actually in the wrong theatre and were watching the movie being advertised).