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 such as romance, mystery, and science fiction, appealing to a wide audience. The production of mass-market paperbacks involves lower-quality paper and binding compared to hardcover editions, which helps keep costs down. They are usually priced lower than trade paperbacks, making them accessible to more readers. This format has played a significant role in popularizing literature and expanding readership since the mid-20th century.