The document discusses the product life cycle and appropriate marketing strategies at each stage. It identifies four stages: introduction, growth, maturity, and decline. In the introduction stage, sales are slow and profits non-existent. Marketing strategies focus on building awareness, using cost-plus pricing, and conducting trials. In the growth stage, rapid market acceptance and substantial profits occur, and strategies shift to penetrating pricing, product extensions, and intensive distribution. During maturity, sales growth slows as competition increases and profits stabilize or decline, so strategies diversify brands and items, match competitors' prices, and encourage brand switching through emphasizing differences. Finally, in decline, sales drift downward and profits erode, so strategies phase out weak products and un