While the secret for Apple's success seems patently obvious to most--as obvious as the form and function of the iPhone 4--a more subtle reason is the company's counter-intuitive knack for disrupting its own product lines.

Will that be an iPad or a MacBook Air Decisions, decisions.

Let's set the stage be asking why can't a Sony or a Toshiba or a Dell emulate Apple's success They've been around the block a few times and have access to equal, or better, resources. A full answer to that question is too long and involved to address in any format other than a Ph.D dissertation. But a willingness (or unwillingness in the above-mentioned companies) to eat one's own progeny--metaphorically speaking--is crucial. In market parlance, it's referred to as disruptive technology. What makes Apple special is that it comes from within the company.

Yes, we cannibalize: Here's an excerpt from Apple COO Tim Cook's comments this week--responding to an analyst's question--about cannibalization of MacBooks by the iPad: "...yes, I think there is some cannibalization. But I also think there's a halo effect...we have introduced millions of people in Asia to Apple through the iPhone. And we're now introducing many more through the iPad, and I think some of those decide to buy a Mac. And so when you look at the Mac growth in Asia at 67 percent, and you look at the Japan growth at 56 percent, and you look at U.S. and Europe growing in double-digits against shrinking markets. If this is cannibalization, it feels pretty good."

No, we don't: The Wintel (Windows-Intel) camp offers the perfect contrast in the Netbook: a lot of potential because it's highly portable and low cost. But the design is not groundbreaking (essentially, a shrunken, stripped-down laptop) and the hardware by design is slow and the build quality is low. Intended result: minimal disruption of the more lucrative mainstream laptop market.

Apple made no pretense about wanting to go after the $300 Netbook market. Instead, it opted for the $500-$600 iPad. A disruptive, market-altering design and inexpensive enough that it would lead some consumers to opt for the iPad instead of a Netbook (include me in that group), while offering the enticing possibility of eating the MacBook Air's lunch at some point.

Or is it the other way around Apple now has the $999 11.6-inch MacBook Air, which gives some prospective iPad buyers pause. Here's what Cook said about that: "And I think Steve said it great when he said, 'If the Mac company were a separate company, and the iPad company were a separate company, what would the Mac company build to compete with the iPad And I think the answer is the MacBook Air.' And I think that's a phenomenal insight, and I think a great way to look at it."

Again, contrast that with Wintel's inability (unwillingness) to grasp the tablet, despite having ample opportunity. PC makers offered "tablets" for years but they have been little more than modified laptops with a half-baked tablet UI, at best. No threat of market disruption or cannibalization here.

Moral of the story: Microsoft, Intel, and PC makers need to begin to self-disrupt quickly or they're going to be competing for a smaller and smaller piece of the pie as Apple and Android-based devices reinvent the personal computer and eat their lunch.