When is a disruptive innovation disruptive?

A disruptive innovation (i.e., one that dramatically disrupts the current market) is not necessarily a disruptive innovation (as Clayton Christensen defines this term). To aid in understanding why some innovations are more (or less) disruptive to the long-term health of incumbents, this article offers terminology and a framework complementary to Christensen's work, focusing on the diffusion pattern of the new product. The framework and model presented herein suggest that when an innovation diffuses from the low end upward toward the high end, a pattern called low-end encroachment, the incumbent may be tempted to overlook its potential impact. Three possible types of low-end encroachment are illustrated: the fringe-market, detached-market, and immediate scenarios. Conversely, when the pattern is one of high-end encroachment, the impact on the current market is immediate and striking. A three-step framework is identified to assess the potential diffusion pattern and impact of an innovation, thereby helping a firm determine the threat or opportunity that an innovation represents.