Disruption

DisruptionDisruption: the incumbent improves past what mainstream customers need while an entrant starts below and improves until it is good enoughPerformance on measures customers valueIncumbent: sustaining innovationEntrant: starts worse, improves fastNeeds: demanding (upper), mainstreamGood enough:mainstream switchesFoothold: low end or nonconsumersTime

Disruption as Christensen described it. The incumbent improves for its best customers and overshoots the mainstream. The entrant starts below what mainstream customers need, from a low-end or new-market foothold, and switches them once it is good enough. A better product aimed at the incumbent's best customers is a sustaining threat, not a disruptive one.