1982 mass-market paperback edition of "Life, the Universe and Everything" by Douglas Adams; typical yellowing due to age can be seen along the outer edges (right and bottom).

A mass market paperback is a small, non-illustrated, and relatively cheap version of a book, usually coming out after the hardback and often sold in airports and supermarkets as well as in bookstores.

Mass market paperbacks are distinguished from hardbacks also by the different business practices that publishers and booksellers apply to them. When booksellers note that books have been in stock a while and have not sold, they may return them to the publisher for a refund or credit on future orders. However, in the case of mass market paperbacks, this "return" usually means stripping the front cover, returning that for credit, and pulping the book itself. Changes in the costs of printing relative to the costs of shipping have led to the creation of trade paperbacks, which are similar in format to mass market paperbacks, but larger (near hardback size) and with different returns policies applied to them.

The mass market paperbacks sold in airport newsstands have given rise to the vaguely defined literary genre of the "airport novel", bought by travellers to while away the hours of sitting and waiting.