Do great companies can fail precisely because they keep serving their best customers too well?

Christensen separates sustaining improvements from disruptive innovations—cheaper, simpler offerings that look unimpressive on mainstream metrics, then climb steadily upmarket. He shows, through disk drives, retailers, and mechanical excavators, how value networks and tidy spreadsheets steer incumbents away from small, low‑margin footholds where disruption takes root. Performance overshoot leaves overserved customers and pockets of non‑consumption; that’s where entrants win. The practical counsel is brisk: ring‑fence autonomous teams with different cost structures, judge progress by learning not margins, and be willing to start small.

If you build, buy, or lead, this book rewires your instincts to spot—and harness—the next wave before it quietly renders your advantages obsolete.