That said, it's equally clear that the supply chain sensibility that enables "everyday low pricing" appears to leave little room for creativity, innovation and impact in CRM. Wal-Mart's creativity, innovation and impact live in its everyday low pricing. Price, not build-to-order, is Wal-Mart's organizing principle for IT architecture and investment.

Only the idiotic or the arrogant would attempt to out-Dell Michael or out-Sam Wal-Mart. But the scalable IT-enabled success of these two giants strongly suggests that CIOs should rethink where value is created in enterprise architectures and, just as importantly, where enterprise architectures can create value. There's no question that you can optimize the efficiency of a supply chain at the cost of being less responsive to customers. For example, I might save my firm 25 percent of hard dollar costs if I eliminate some distribution centres and carry less inventory. That decision would probably make my company less responsive to customers, since they might then experience more stock-outs. But that trade-off may be worth it. What I pay for that extra inventory may cost more than what I lose in sales from customers who don't find the stock they want. The question is: What's the better business investment?

Conversely, I might be able to command a 20 percent premium from my most profitable customers, but only if my top five suppliers agree to meet my just-in-time demands for customized products. Yet my suppliers might be reluctant to do that because it may put their other vendor relationships at risk.

In other words, the notion that organizations can optimize CRM without undermining SCM efficiencies - and vice versa - is a chimera. There are always trade-offs. The business issue is: Are these good trade-offs or bad trade-offs? The technical issue is: Do your architectures and implementations allow your company to quickly and cost-effectively act on these business trade-offs once the decision has been made? Let's reframe the question: Does the company get a better return from investing in its SCM? Its CRM? Or from investing in the technical and business intersection of SCM and CRM?

I think one of the most important roles the CIO will play tomorrow is facilitating C-level conversations around determining whether the business is better off treating SCM and CRM as complements or as rivals. The CIO's challenge will be to assure that (no matter what the decision is) the technical architectures are robust enough to handle it.

If you're Dell, you've grown up understanding this. If you're Wal-Mart, you've grown up deciding that asymmetric investments in supply chain define your global competitive guillotine. But if you're Target? If you're GM or Ford or Toyota? If you're Procter & Gamble? If you're Citigroup or Fidelity? The answers aren't so clear.

Ultimately, organizations are going to have to expend more time, thought and ingenuity determining what processes should cut across the boundaries of supply chain optimization and CRM. Different organizations are going to come to completely different conclusions. In the same way that IBM, Apple and HP can't be Dell - and Target or Sears can't be Wal-Mart, and Delta Air Lines can't be Southwest - deciding how and where customer networks should be linked to supplier networks will be an idiosyncratic process. Successfully implementing those idiosyncrasies will be the CIO's dominant operational challenge and the organization's ultimate source of value differentiation.

Michael Schrage is codirector of the MIT Media Lab's eMarkets Initiative