Introduction, 394. — The definition of marketing, 396. — Retailing costs, 398. — Wholesaling costs, 398. — Manufacturer's marketing costs more difficult to estimate, 399. — Total cost of marketing in excess of 24 billion, 1929, 401. — Marketing costs compared with value added by manufacture, 402. — Income from marketing, 403. — Census of distribution facilitates estimate of marketing employment, 404. — Total marketing employment in excess of 8 million, 1929, 406. — Employment in marketing increased rapidly during the last two decades, 407. — Conclusions, 411. — Increasing specialization as a cause of increasing marketing costs, 412.