• some differences may have business significance. For instance, Google and Amazon require users to upload their music, which can take many hours or even days, and some of your music tracks might be very low quality. Apple’s service matches your local collection and places high-quality versions of the music online automatically. It’s unclear if this is a permanent advantage because both Google and Amazon could negotiate similar deals with the music companies. Google and Apple can sell users expensive smartphones to play cloud music, whereas Amazon has no proprietary music player.