product life cycle

Four distinct but not wholly-predictable stages every product goes through from its introduction to withdrawal from the market: (1) introduction, (2) growth in sales revenue, (3) maturity, during which sales revenue stabilizes, and (4) decline, when sales revenue starts to fall and eventually vanishes or becomes too little to be viable. As a product moves through these stages, its pricing, promotion, packaging, and distribution are re-evaluated and changed if required to prolong its life. In summary, it is the journey from "new and exciting" to "old and dated."