Contents: evolution of marketing methods; mail selling plans based on statistics; economic value of truth in marketing by mail; using the mails to make sales; manufacturers who have become merchants by mail selling; opening new territory and increasing sales for jobbers and retailers; how the mails are used to strengthen the hands of the sales force; building the prestige of an institution by mail; financing a mail selling campaign; regulating the market by mail; organized knowledge in mail selling; cash value of mailing lists; relation of publicity to selling by mail; using the mails to keep customers sold; place of mail selling in merchandising.