Here is a piece by Daniel Menaker (editor of Grin and Tonic) from The Barnes and Noble Review on the language of book flaps.
It’s got 16 rules for writing the copy on books flaps. Words to use: “stunning,” “deeply,” “enthralling,” “gritty,” “original,” “remarkable,” “magical,” “ground-breaking,” “arresting,” “dazzling,” “heartbreaking,” “compelling,” “devastating,” “captivating,” and of course “best-selling”even out of context, as in “So-and-so is often compared to the best-selling novelist….” Check it out.
But I wonder, what’s going to happen to the flap in the age of ebooks?