Joffre Street Productions made this trailer for me in 2007 for the launch of Dark Space.
I personally love the idea of them - in the end it all comes down to the quality of the product. As I mentioned in the comments section, Random House have done a beautiful trailer for the release of one of their new books, Fallen. The Fallen book trailer will be shown in cinemas preceding Twilight screenings. Not sure if this is the exact video for the cinemas - I saw a different version, but you get the idea: