I want to say this as someone who generally enjoys Apple products but does find them a bit overpriced, so please withhold fanboy accusations in one direction or another.
An executive at our company recently gave a speech to our team about how impressed he was with Apple's sales theories. He says that he sees Apple as successful because they don't just make products that fit into a certain line - they make new products.
As in... what's an iPhone? If you had to describe an iPhone to someone, what would you say? You would say maybe, "It's a smartphone that functions using a touch screen instead of a keypad and has access to a very large number of small applications and games." Go into an Apple Store, though, and ask a rep what an iPhone is, and he'll say, "Well, it's the iPhone. Here, try it out." Then he'll give you one and let you play with it for awhile.
When you watch a commercial for the iPhone, you never hear things like, "blazing fast 1.5 Ghz speed," or "some of the largest capacity on the market." You also never hear the word "smartphone." When you watch an iPhone commercial, you see people browsing the internet or playing games or chatting on IM. By the way, you might recall how the original iPod commercials never said the words "mp3 player" - they just featured silhouettes of people dancing. And when has Apple ever referred to an iPad as a "tablet computer?"
Whenever Apple markets a product, they don't describe it to you. They tell you its name, they show you what it does, and they try to get you to think of it as a brand new device that has no relationship to anything else on the market. Getting back to our executive at our company, he talked about developing our product suite with a new name that hadn't been used before, and talked about how he'd set up their booth at the last major trade show to have tons of demonstrations, where people could just interact with the product rather than reading a ten-page fact sheet about all of the new and interesting things that product can do. We had a ton of interested customers at that booth this year.
You can't help but compare that stuff to Microsoft, who is always playing catch-up. "Here's OUR mp3 player! Here's OUR user-friendly OS! Here's OUR smartphones!" Microsoft markets its products as the MS iteration of products that always exist, giving them that special MS touch that makes those products better. Apple markets its products as... Apple products. I don't care whether you love or hate Apple or something in between - you have to respect that strategy.