The document discusses the product life cycle, which includes four main stages: introduction, growth, maturity, and decline. In the introduction stage, sales volumes and market share gradually grow through reduced stock turnover and coverage of more sales points. The growth stage involves positioning in the market segment, ongoing promotion activity, and increased repetition of purchases. During maturity, market penetration reaches optimal levels and profitability is highest. In decline, demand decreases with no further growth, ultimately requiring the product's withdrawal from the market if economic results cannot be obtained.