Every product you've ever bought is somewhere on a curve that starts with excitement and ends with a clearance bin. The Product Life Cycle framework has been around since 1950, and despite constant predictions of its obsolescence, marketers keep coming back to it because it captures something fundamentally true: markets have seasons, and strategy needs to change with them.
I think the PLC framework gets underrated precisely because it looks simple. Four stages. A bell curve. Intro-level marketing students learn it in week two. But the companies that actually adjust their strategy stage by stage outperform the ones that run the same playbook from launch to sunset, and that gap has only widened as product lifecycles have compressed.
The Product Life Cycle concept started with Joel Dean, an economist who wrote about the "cycle of competitive degeneration" in his 1950 Harvard Business Review article "Pricing Policies for New Products." Dean noticed that products lose differentiation over time as competitors copy features and customers become less price-insensitive. He was really talking about pricing strategy, but he'd sketched the underlying dynamic.
Theodore Levitt turned that observation into a strategic framework with his landmark 1965 HBR article, "Exploit the Product Life Cycle." Levitt's contribution was converting the descriptive curve into a prescriptive tool — if you know where your product sits on the lifecycle, you can anticipate what's coming next and adjust before competitors force you to.
Philip Kotler then built the PLC framework into his foundational marketing management textbooks, connecting each stage to specific marketing strategies. Between Kotler's textbooks and Levitt's HBR piece, the PLC became one of the most taught frameworks in business education. It's been refined and criticized and updated for 60 years, but the core shape holds.
The product is new to the market. Customer awareness is low. Sales grow slowly because you're educating people about something they didn't know they needed. Marketing spend is high relative to revenue. Profits are typically negative or minimal.
The strategic question in Introduction is: how fast do you want to build the market? Levitt and Kotler identified four commercialization approaches:
Sales accelerate as the market accepts the product. New competitors enter, attracted by proven demand. Distribution expands. Marketing shifts from awareness-building to differentiation and brand loyalty. Profits improve as economies of scale kick in.
The strategic question in Growth is: how do you build defensible market share before the market matures? Companies that invest in brand, distribution, and product improvement during Growth tend to capture the strongest positions. Companies that milk early profits often lose ground to more aggressive competitors.
Netflix's streaming business in 2012-2018 is a good Growth stage example. Subscriber numbers were climbing rapidly. Competitors were entering (Hulu, Amazon Prime). Netflix invested heavily in original content as a differentiation strategy, knowing that the commodity phase (Maturity) was coming and that content exclusivity would be the moat.
Sales peak and level off. Market saturation sets in. Competition is intense. The weaker competitors start getting squeezed out or acquired. Marketing focuses on differentiation, customer retention, and squeezing margin from an established base.