The Library of the Unwritten clearly caters to book readers more than every book does in general: Fantasy where the hero is a supernatural librarian, on a quest to retrieve souls and books? Starring in a conflict between Hell and Heaven? Hell yeah.
Despite the tempting setup, it couldn’t catch my attention at all: It relies on the natural interest of readers towards libraries, then doesn’t back it up. Good-enough characters, not-good-enough dialogue … there’s nothing that stands out as bad, but there’s nothing that stands out at all. I didn’t care about the characters and stopped reading.