Carr argues that computers have become so cheap and powerful that computer ownership is widespread. The argument goes like this: if nobody has a computer except your company, then you have a real advantage over anyone who does data processing with pencils and card files. But if everyone has a computer, nobody has a competitive advantage.

Here’s the nub of his argument: “What makes a resource truly strategic – what gives it the capacity to be the basis for a sustained competitive advantage – is not ubiquity but scarcity.” Consequently, companies should treat IT as a cost to be shaved, not an investment to be valued.

The first counter-argument is that there is still plenty of uncommoditised IT out there. Yes, the PC is standardised and widely available, but it only accounts for 12% of IT budgets globally. (Even within the PC market, there are significant differences between vendors.) There is plenty of room for companies to innovate in other areas. The PC’s very ubiquity is a precondition for this innovation. Business-changing projects like CRM or ERP wouldn’t be possible without a PC on every desk.

Then there are tough-minded statistical surveys that contradict his findings. In six industries, investment in IT correlated to improved productivity, according to a 2001 McKinsey study. The correlation was far from universal, but it shows that IT can make a difference to performance. The outstanding example from that study was Wal-Mart, who achieved approximately 40% more productivity than its competitors because of the way it used IT.

IT can also make a difference to the productivity of individual employees. According to research by the Office of National Statistics, there’s a strong correlation between the number of staff using computers and the internet and the value added per worker.

A Formula 1 driver will outpace the average motorist in a race, even if they are driving identical cars. In other words, technology is only part of the equation. “It ain’t what you do but the way you do it.” Extracting value from IT requires changes to business practices, not just big bang spending.

Carr compares IT to other kinds of infrastructure, like roads or railways. It is “essentially a transport mechanism” for carrying information. If everyone has common access to roads, trains or the telephone system, he insists, nobody gets a competitive advantage from them. However, this misses a fundamental point about information. It is more flexible than physical transport networks. Data collected for one purpose can be used for something else. It’s like buying a ship and turning it into a plane on weekends.

The value of information is clearest in successful internet companies like eBay or Google, who have been able to repackage information in different ways to create value. An initial technological leap can create huge barriers to entry. In a follow-up article, Carr says “Just because we continue to see new innovations in IT does not mean that it pays to be a pioneer.” Shareholders in both companies would disagree.

On the other hand, outmoded IT systems can hold companies back. Retailers, such as Wal-Mart or Tesco, use IT to manage their supply chains more effectively than their competitors. Low-cost airlines are more nimble than big carriers in part because of smarter IT operations. Carr agrees: “Even if the ability to get advantage has been neutralised the ability to fall behind is still there.”

Carr’s critics also take issue with the premise that IT has become a commodity. The CTO of General Motors said “Brakes are a commodity, but I don’t think anybody would say they don’t matter.” In other words, IT is ubiquitous because it is important, not because it is cheap.

Others separate the Information from the Technology. As Steve Ballmer said, "Information is the lifeblood of business, and software is what gives people and businesses the ability to harness it. It enables companies to constantly hone their competitive edge.” (he also called Carr’s argument “hogwash.”) Companies need the right technology to make sure they can harness the right information.

Executives might not be able to turn a given technology into a permanent competitive advantage. Perhaps what is more important is the ability to surf a rolling wave of technological change. Analyst firm Gartner argues that the central issue is not technological innovation per se (as Carr believes), but how companies convert IT investments into business outcomes. “Companies that use IT to create business value,” concludes the report, “have integrated business and technology leadership, management discipline, sound processes, and a focus on making the enterprise more effective.” In other words, business leadership and technology leadership go hand-in-hand.