Throughout history, successful movies have had successful trailers. If you think about Jurassic Park, Spider-Man, Pirates of the Caribbean, and a select others, you will notice that you saw their trailers everywhere. This is no fluke. It is also no fluke that new movie trailers are always paid close attention to by movie geeks around the net. Next time you go to the movie, try to remember what the trailer was like. I be you will be surprised that it showed you many important scenes.

A teaser is a short trailer that might not actually show scenes. This is true with "The Dark Knight" teaser. It only has a voice over, but satisfies those movie fans who can't wait to see it.