Marketing myopia
Theodore Levitt's 1960 argument that companies decline when they define themselves by the product they make instead of the customer need they serve: the railroads saw themselves in the railroad business, not transportation, and lost passengers and freight to cars, trucks and planes. The cure is a market definition broad enough to see substitutes coming; the opposite trap is a definition so broad it gives no direction.
Where it's used
Used in strategy reviews to check whether a company defines its market by its product or by the customer need behind it. Good to revisit when new technology or substitutes start winning customers in the category.
Example
The film company that built a digital camera
KodakA Kodak engineer, Steven Sasson, built one of the first digital cameras in 1975. The company kept defining itself around film, its most profitable business, while digital photography and then phones took over picture taking. Kodak filed for bankruptcy protection in 2012. The need, keeping memories, never went away; the product Kodak was attached to did.