Theodore Levitt's 1960 Harvard Business Review idea that companies fail when they define themselves by the product they make rather than the customer need they serve.
When defining the business and its competition, writing positioning, or when a category is being disrupted by substitutes you did not see coming.
Levitt's railroads, which saw themselves in the railroad business instead of the transportation business and lost to cars, trucks and planes; a print shop that defines itself as 'helping local businesses get noticed' and adds signage and digital.
A foundational lens for every industry, especially mature ones. Flagged when a company describes itself only by what it makes.
