We must consider many factors before choosing to deselect a book.
Jennifer LaGarde's F.R.E.S.H method and M.U.S.T.I.E. guide us. A book should ideally meet a few categories.
Sometimes a book hasn't circulated and just needs to be displayed or book-talked--feel free to give forgotten books a second chance! If it still doesn't circulate, then you can say goodbye to it.