Increasing trade concentration in retail fields, particularly in consumer products, poses several problems for manufacturers. Among the greatest are (1) increasing retailer control of the marketplace, (2) more intense competition among sellers, (3) lack of brand availability in some markets, (4) increasingly larger promotion budgets required of manufacturers, and (5) changes in sales force personnel and activities. Some of the suggested changes in the marketing mix are (1) market investigation, (2) new distribution systems, (3) revised promotional efforts, and (4) production differentiation.