Trade paperback books, hardback books, audio books, textbooks, and more through an online swapping club. Visit their website and list books you’d like to swap with other club members. Once a book is requested, you mail it to the club member. In return, you may choose from nearly four million available books. You pay postage for the books you send out and the books you receive come to you postage-paid. Books you request are yours to keep, or swap again.