The direct market is the dominant distribution and retail network for American comic books. The concept of the direct market was created in the 1970s by Phil Seuling. It currently consists of one dominant distributor (Diamond Comic Distributors) and the majority of comics specialty stores, as well as other retailers of comic books and related merchandise. The name is no longer a fully accurate description of the model by which it operates, but derives from its original implementation: retailers bypassing existing distributors to make "direct" purchases from publishers. The defining characteristic of the direct market is non-returnability: unlike bookstore and newsstand distribution, direct-market distribution prohibits distributors and retailers from returning their unsold merchandise for refunds. In exchange for more favorable ordering terms, retailers and distributors must gamble that they can accurately predict their customers' demand for products. Each month's surplus inventory, meanwhile, could be archived and sold later, driving the development of an organized market for "back issues."