As information technology has grown in power and ubiquity, companies have come to view it as evermore critical to their success; their heavy spending on hardware and software clearly reflects that assumption. Chief executives routinely talk about information technology's strategic value, about how they can use IT to gain a competitive edge.

But ,scarcity, not ubiquity, makes a business resource truly strategic -- and allows companies to use it for a sustained competitive advantage. You gain an edge over rivals only by doing something that they can't.

IT is the latest in a series of broadly adopted technologies -- think of the railroad or the electric generator -- that have reshaped industry over the past two centuries. For a brief time, these technologies created powerful opportunities for forward-looking companies.

But as their availability increased and their costs decreased, they became commodity inputs. From a strategic standpoint, they no longer mattered.

That's exactly what's happening to IT, and the implications are profound.