Apple iCloud vs. Google Music vs. Amazon Cloud

Apple iCloud vs. Google Music vs. Amazon Cloud: "Amazon was the first to announce its Cloud Drive storage service a few months back, and it’s the only cloud-based music service that is completely available to users as of today. Google recently announced its highly-anticipated Google Music Beta service, but like the name suggests, it’s still in an invite-only beta testing stage, although anyone can request an invite and hope to be chosen."