Sustaining vs Disruptive Innovation

The distinction between sustaining and disruptive innovation is not a continuum but a categorical difference, and conflating the two produces the strategic errors that fill Christensen's case files. Sustaining innovations improve existing products along the dimensions existing customers already value — the fast thing faster, the reliable thing more reliable. Incumbents almost always win sustaining competitions because their deep customer knowledge, distribution channels, and organizational capabilities give them overwhelming advantages. Disruptive innovations do something categorically different: they serve different customers, or existing customers in contexts where the incumbent's product is unavailable, with products that existing customers would consider inadequate. The inferiority is real; it is also, structurally, irrelevant. Applied to AI, the distinction reveals that the same underlying technology sustains in one business model and disrupts in another — and that the strategic implications are opposite.