Remaindered books are copies publishers sell to retailers at a discounted price because demand for the book is well below the number of copies printed. Sometimes a publisher remainders a book to clear out inventory space. Retailers then sell the remaindered books at a discounted price. Remaindered books usually have a black mark so they can’t be returned or sold for the original full price. The mark is a dot or stripe across the top or bottom of the book on the outside of the pages.