A very interesting point. As you know often when ever you read a book which is a serial, the author will have the first 20 or so pages of the next book at the end of his or her book.
So I think that having a trailer would be a great idea.
I wrote Stephanie, after part of Midnight Sun was released on the internet and said “Cheer up it might just turn out to be one of the greatest marketing moves in book selling history.”
We will see when it is released. The problem is since it will easily sell 12,000,000 hard back copies, whose to say if part of “Suns” premature release had a positive or negative effect.