Mass market paperbacks are affordable books that are produced in large quantities and sold in various retail outlets, including supermarkets and drugstores. They are typically smaller in size, making them portable and easy to carry. These books often feature popular genres like romance, mystery, and science fiction, appealing to a wide audience. The production of mass market paperbacks involves lower printing costs, allowing publishers to sell them at a lower price point compared to hardcover editions. This format has made literature more accessible to the general public, contributing to the popularity of authors such as Stephen King and Agatha Christie.