Apple did a two things very well:
1) Apple basically cornered the "hipster" market.
2) Its products are very nicely designed, excellent user experience.
On the first point, a big part of their marketing played on the view that PCs are stuffy and geeky, Macs are cool and made for everyone else. Apple really pushes on the idea that their devices are made for movies, music, games, books, web. Software related to those purposes are beautifully designed, you actually
do feel cool using their software.
On the second point, Apple markets "beauty" as a feature. I was really impressed with its movie editor, even the webcam software is beautifully designed, I prefer the iTunes interface over all other music organizers (and I can't tell you how much I love that trippy iTunes visualizer), MacOS is gorgeous from end to end. More than anything else, the iPod
evolved very gracefully, from this ugly thing with bulky buttons and LCD display like a graphing calculator, to gradually integrating the buttons to the circular touchpad, to full color high resolution dispays, to a family of touch-screen devices supporting a whole mass of apps. Very nice nice design, looks very modern, does a lot more than a vanilla MP3 player.
Apple products generally stand out with one or two "killer features". Circular touchpads set early-generation iPod's apart from other MP3 players, MacBook Air's weighs about 3 lbs, touch screen iPhones were a
radically departure from traditional phone design and set the standard for user experience on all other touch screen phones.
All Apple products compliment each other fairly well, which makes it easy for people to buy one Apple product then another and another, all of their products integrate nicely with iTunes, all of them have a very consistent user experience across all of their devices.
As many good things as I have to say about Apple, their products aren't for me. I like to
tinker under the hood, I'd like to
use my iPad like a computer, I stopped using iTunes because it keeps adding QuickTime and Safari under my nose. I really love the iPhone, but decided to whore myself for Android instead.