Dictionary.net

• An association of persons who buy new books for circulation among themselves.

1899 - The american dictionary of the english language.
By Daniel Lyons

• A firm that sells books to members by mail or internet. The member must buy a certain amount of books to get discounts. It is run on an opt in method and some opt out methods as well.

1910 - Black's Law Dictionary (2nd edition)
By Henry Campbell Black