They say a picture is worth a thousand words, but a film is worth a million.
Book trailers are incredibly powerful vehicles for communicating the nature and emotional trajectory of a story. When an author comes to me for a complex trailer, I work with the author to understand the arc of the story, the imagery of the setting, and the characters. This takes time. Which means the overall effort can take several weeks.
But just like a great story doesn’t emerge overnight, neither does a great book trailer.