One theory surrounding the iPod's runaway success is the idea that those who buy the MP3 player will be exposed to Apple's computers and possibly become switchers. BBC Online's David Reid takes a look at that theory in light of the recent introduction of the iPod nano and asks: "But is the success of iPod and iTunes obscuring the struggle Apple is having in increasing its global market share in its core business: computers?"

Mr. Reid quotes the company line as stated by Phil Schiller, Apple's vice-president of worldwide marketing, and then moves on to MacUser magazine's Christopher Phin, who says: "It is something that Apple has decided they like the sound of and that they're using as a way of convincing people, possibly themselves, that the Mac is indeed doing everything it can in the market place and building its market share the way they want it to."

Mr. Phin also reiterates recent speculation that Apple made the Intel version of Mac OS X easy to crack, "so people will buy very cheap IBM PCs from Dell and other manufacturers like them, that are much less expensive than Apple's own kit. They will then run the operating system on that because Mac OSX is a fabulous operating system to use.

"Then, two or three years down the line, Apple will turn round and officially start selling Mac OSX for Intel boxes. And, of course, everyone who is then using it already will upgrade."