They do, because trailers are supposed to generate interest.
However, what I do find interesting is what the trailers tend to show and how it is in context during the movie.
“They do, because trailers are supposed to generate interest.”
Yeah, but it’s a real pisser if the rest of the movie turns out to be not as good as the trailers when it turns out they were practically the ONLY good parts!
Generally the funnier the trailer, the more unfunny the entire movie will be because they tend to show the only funny scenes in the trailer.