Late last year, market research firm MetaFacts dealt Apple's image a body blow when it claimed that almost half (46%) of Apple's customer base were age 55 and older, nearly double the share of average home PC users (25.2%).

Faced with the possibility that nursing home residents in silhouette might scuttle its iPod ad campaign, Apple said that only about 20% of Mac users were over 55, while being tactful enough to add that it welcomed customers from 1 to 100.

It might have ended there, with the snickering of pundits and those opposed to Apple's monopolization of "cool," which is to say the online music market.

But now Internet metrics firm Hitwise has reopened the discussion by claiming that, based on recent traffic data, "the majority of traffic to the Apple Web site came from users under 45, while the majority of traffic to the Microsoft Web site came from users over 35, with a full 22 percent of its traffic coming from those in the 55+ age bracket."

In a blog post that recaps an article she wrote for iMedia Connection, Hitwise research director LeeAnn Prescott emphasizes the decrepitude of Microsoft's customer base by noting that in keeping with the company's demographic skew, "the spokesman on the Windows Vista promotional site is Tom Skerrit, a 73-year-old actor." (Marketers may want to add extra exclamation points here to emphasize the desirability of younger customers.)

And as Prescott sees it, Apple's marketing department is actively capitalizing on this age gap. "Even Apple's advertising team picked up on this difference, casting an older geek as a PC and a young hip guy as a Mac in its television commercials," she claims.

It's tempting to say that Microsoft is promoting Vista with the tagline "The Wow Starts Now" because most of its customers don't have much time left. But that's about as fair as insisting that Apple customers can't actually eat the fruit for which the company is named because of denture limitations.

As Benjamin Disraeli supposedly said, there are three kinds of lies: lies, damned lies, and statistics. That's essentially what a recent Forrester Research report pointed out in noting that technology studies tend to confirm the political and social biases of their sponsors. It would not be surprising to find that data about the average age of Apple and Microsoft customers is similarly variable.

And in the absence of any real clarity on this issue, perhaps it's best to observe that every dollar, no matter who it comes from, counts.