McGrath, leaving a message in a library book is a different thing altogether, it seems to me. At a library, the reader has already made a decision to at least pick up the book, and potentially take it out. The genius of this approach is to get a book into a reader's hands in an unplanned way, so that the next person is at least exposed to a book (s)he never might have contemplated, and broaden his/her exposure. Indeed, it might get a former reader restarted in the lovely pastime of reading.

Dave Oesterreich