General Rules in the Book Bazaar:
(5) No swapping books-for-books unless the swap is between two "Boxers" (Boxers = subscribers to Box-O-Books). For example, posting "I will send you this book if you will send me that book" or "I will send any three books from my bookshelf for this one book I want" is not permitted unless both members are Boxers. If you are a Boxer, why not peek into other Boxers' bookshelves from the Box-O-Books area to see if books you want are available? You can save a lot of postage and credits this way!