Mac sales surge but did they really blow away PC sales?

The colorful charts are pretty impressive and the percentages are pretty big. But reports about surging Mac sales in the enterprise are a bit misleading.

That's not to take away anything from Needham analyst Charlie Wolf, who analyzed IDC's second quarter report on PC shipments, or Fortune's Phillip Elmer-Dewitt, who shared the details of Wolf's report today on his blog. But any comparison of growth rates for two competing sides - in this case Mac vs. PC - must consider the starting point for both.

The PC has a huge market share lead over the Mac and, as such, even a small percentage gain in shipments can be significant. At the same time, the Mac market is much smaller so, a brisk number of sales in a particular quarter could lead to some impressive growth - as its measured in percentages, that is. Consider the bullet points that Fortune used from the Needham and IDC reports.

• At 35%, Mac shipment growth in June easily exceeded the market's growth rate of 20.9%.
• Mac shipments grew 31.4% in the home market, topping the market's growth rate of 25.2%.
• At 49.8%, the Mac's growth in business was three times higher than the market's 15.7%.
• Mac shipments in government grew 200%, sixteen times faster than the market's 12.1%.

Better yet, let's look at one of the colorful charts that give us a visual picture of what's happening in PC shipments.

As a Mac owner, I've certainly done my fair-share of converting others to dump Windows and buy a Mac. And on its quarterly earnings calls with Wall Street analysts, Apple regularly offers some insight into the number of new Macs that were sold to first-timers. In that respect, I'm not looking to rain on Apple's big-headline moment.

I'm just saying that, when you're looking at percentages, colorful charts don't always tell the full story.

(Image credit: Fortune.com; Image source: Needham, IDC)