Do we have this? Those quotes on the back of books (or on movie posters, "best comedy of the year by far" for a film released in january) saying how great the subject is (and sometimes just copy-pasted by the publisher) from other authors or reviewers. Usually a complete lie, or so utterly generic that it gives no clue as to what the book is about (although Terry Pratchett
once used a critic's denigration of a book as the blurb for it), and occasionally giving away the entire plot. An integral part of the publishing industry these days.