“The shots are shorter and shorter and shorter, and more fragmented,” Dixon says. “There have been a number of studies that demonstrate that the average length of a shot in a film have been shrinking every single year, because audiences absorb information faster — and there’s also a sense that you don’t want to bore them.”

I personally don’t watch trailers - I think they give away too much and lessen the surprise/freshness of seeing the particular action scene or smart/witty/funny dialogue in the actual movie. But this is an interesting read about what all goes into producing trailers for the masses...