A book sales club is a subscription-based method of selling and purchasing books. It is more often called simply a book club, a term that is also used to describe a book discussion club, which can cause confusion.
Each member of a book sales club agrees to receive books by mail and pay for them as they are received. This may be done by means of negative option billing in which the customer receives an announcement of the book or books along with a form to notify the seller if the customer does not want the book. If the customer fails to return the form by a specified date, the seller will ship the book and expect the customer to pay for it, or the business may operate via a "positive option" in which the customer is periodically sent a list of books offered, but none is sent until the customer specifically orders them. The offer of a free book, often a large one, is a frequent enticement to membership. The Compact Edition of the Oxford English Dictionary for years served this purpose. Some clubs offer new members other (non-book) free gifts, such as book notes or reading lights.
Some book sales clubs are "continuity" clubs, which send members a certain number of books (selected by the club or the member) every month until the membership expires or is canceled. Harlequin Book Clubs are typical of such clubs. Other book sales clubs are "commitment" clubs, which require members to order a certain number of books in order to fulfill the membership obligation and cancel the membership. Most Book-of-the-Month Clubs are commitment clubs.
Book sales clubs typically sell books at a sizable discount from their list prices. Often, the books sold are editions created specifically for sale by the clubs, and are manufactured more cheaply and less durably than the regular editions.
The Book-of-the-Month Club (founded 1926) is an early and well known example of this kind of business. Others include the Science Fiction Book Club, the Mystery Book Club, and the Quality Paperback Book Club, all of which are run by Booksonline / Doubleday Entertainment (a subsidiary of Bookspan). The largest book of the month clubs have millions of members.
Time-Life book produced a large number of book series in the book sales club format, including the Time Reading Program.