Horizontal lock-ins are harder to see than vertical ones. When you buy a movie or TV show or book from iTunes, you know it'll only work on Apple devices. If you own anything else, all that content might as well be dead to you. When you buy a movie or TV show or book from Amazon or Google, however, it can feel like a safer investment, like you can play it anywhere and on anything. But it only seems that way. The truth is, you can only ever play your content on the devices the content and service provider — any provider — allows you to play them on, and only for as long as they allow it. We're just as locked to Google's will and servers, and Amazon's, and anyone else's. And we will be until such time as DRM (Digital Rights Management) is dead.