If that's the case, I'd bet it's for license reasons. An AmazonMP3 purchase made after Cloud Drive is launched could be described as having been copied for pers

If that's the case, I'd bet it's for license reasons. An AmazonMP3 purchase made after Cloud Drive is launched could be described as having been copied for personal use, at the time of purchase, to your Cloud Drive. Allowing previously purchased tracks to be streamed without first uploading them looks more like what Lala was doing, and they had to negotiate streaming licenses. Though I'd wonder if there is any real implementation difference in Amazon's case.