Apple's iTunes was originally conceived (and run for a number of years) as a more-or-less "break even" music service that was little more than a value-added feature driving buyers to the high-margin iPod line. Today, the iTunes empire pulls in $13.5 billion annually, of which music sales still play an enormous part -- around $4.4 billion, of which about $3.4 billion goes to music publishers large and small. This would mean that iTunes alone accounts for about 60 percent of the music industry's $5.6 billion in digital music sales.
