It should really show readers why they have to read through your book and let them know what they might assume; it’s an advert for the book. It's not your individual statement on why you wrote the book. (This frequently goes on the interior book jacket flap for hardbacks.) Visitors https://www.diigo.com/item/note/akgn0/1vso?k=c01457115180e486e5935af8f03b6f96