I'd suggest it's both, and that they work together.<p>I LIKE using my Mac and my iPhone. I DON'T like using my BlackBerry and Windows machine.<p>All of those machines offer pretty good usability (I can use them all to get things done). But I'm not attracted to the BlackBerry and the Windows box. It's not that they're ugly, just . . . unattractive.<p>I suggest Apple has tapped in to something innately human: we like pretty stuff. Or at least enough people do to make the iPhone the best selling smartphone in the world. . . .<p>The usability Apple mixed in with the lipstick makes these things irresistible for large chunks of the market. These things sell like crazy.