Grandparent is probably thinking along the lines of a local monopoly, analogous to an old company town: <a href="http://en.wikipedia.org/wiki/Company_town" rel="nofollow">http://en.wikipedia.org/wiki/Company_town</a><p>The analogy is not perfect, since you can buy mp3s and movies and ebooks from other services.  But on iPhones and iPads the barriers to getting content from non-iTunes sources is certainly higher than it otherwise would be on a regular Mac (or any other PC for that matter).<p><i>full disclosure: lifelong Apple user</i>