A further analysis of the iTunes Store by noted analyst Horace Dediu of Asymco estimates that sales of Mac and iOS software from Apple (such as OS X upgrades and the iLife and iWork programs) have turned the store from a low-margin "break even" operation into a significant profit center, clearing an estimated $2 billion in annual revenue. In part, the profit comes from economies of scale as the various iTunes stores have seen massive growth in the past few years, but Apple's own software sales are the most profitable portion of that.
