This may be a sore subject, as I know a lot of folks who have produced trailers for their books, but this article in Slate got me to wondering about the key question regarding trailers:
Does anyone know if they work?
For me, personally, no. I can't imagine buying a book based on a video trailer. Part of this is because I can't imagine watching a video trailer, unless someone I knew asked me to check one out for him. If I wanted to spend my time watching television, I'd watch television. Books and TV/movies are completely different story-telling media. The video is a far more passive experience for the viewer than a book is for a reader. I have a suspicion those who watch a lot of videos don't read a lot.
It might be a cool thing for someone established in a certain kind of story (Stephen King, J.K. Rowling) to let fans know their new book is available, because their readers are looking for something of an extraordinary experience. (Using "extraordinary" to mean "beyond ordinary," not "great," as it is sometimes used. Not that their writing isn't great; their subjects are extraordinary.) Video might appeal to them. To me, not so much.
I'm a writer, so this might make me the oddball. (Okay, not just writing does that. I mean in this specific situation.)
What do you think? Do book trailers influence you? Has anyone ever seen any empirical evidence that implies they're wirth the time and effort?