Actually letting you store your music on its Cloud Drive servers isn't where Amazon stands to make its most significant gains, though. Cloud Drive is merely a mechanism to draw you in. Making Amazon a focal part of your mobile experience is where the company's real value lies.

Just look at Amazon's Cloud Player app for Android: If you use Cloud Drive, you'll inevitably use Cloud Player. You might even use it as your primary music playing application, online and off, since the program works with both cloud-stored music and locally stored songs. And what's prominently placed on every single screen within the Cloud Player app? A link to buy more songs from Amazon's MP3 store. The "Store" link itself is visible at the top of the screen throughout the entire Cloud Player application. When you're listening to a song, a second link appears offering to show you more selections from that same artist.

The Amazon shopping integration is seamless, too: Tapping any of the store-aimed links opens a page right within the same app, without so much as stopping the song you're playing. Since you're using Cloud Player, you're already signed into your Amazon account -- and that means you can make a purchase without ever having to enter a credit card number.

And remember: This is all on Android. Amazon isn't launching Cloud Player on iOS. There is no Windows Phone version. The focus is squarely on Android -- and with good reason.

One of Android's strengths as a platform is the fact that it doesn't force you to use any particular program for managing your music. There is no iTunes; instead, you can pick from , or you can forgo the graphical interface altogether and just drag and drop files at will. The freedom provided by this approach is empowering, but it also means there's no universal one-stop place to shop for multimedia content and have it beamed directly onto your device. There is no de facto store.