Price fixing requires a conspiracy between sellers or buyers. The purpose is to coordinate pricing for mutual benefit of the traders. For example, manufacturers and retailers may conspire to sell at a common "retail" price; set a common minimum sales price, where sellers agree not to discount the sales price below the agreed-to minimum price; buy the product from a supplier at a specified maximum price; adhere to a price book or list price; engage in cooperative price advertising; standardize financial credit terms offered to purchasers; use uniform trade-in allowances; limit discounts; discontinue a free service or fix the price of one component of an overall service; adhere uniformly to previously-announced prices and terms of sale; establish uniform costs and markups; impose mandatory surcharges; purposefully reduce output or sales in order to charge higher prices; or purposefully share or pool markets, territories, or customers.