What you're describing isn't a walled garden or an ecosystem. Amazon is selling a product but there's no consumer lock-in. I can buy music, movies, or ebooks on

What you're describing isn't a walled garden or an ecosystem. Amazon is selling a product but there's no consumer lock-in. I can buy music, movies, or ebooks on Amazon and put them on an iPad, a Kindle, or my computer using common software. They may have a dangerous hold on the market because of their size but that's more like a monopoly than a walled garden.