[quote name='Graystone']Also I wonder how much apple makes on each song sold.[/QUOTE]
Not a whole lot. It's mainly a vehicle for iPod sales.
edit: Pay close attention to Steve Jobs' comments...
“I hope that every customer, artist, and music company executive takes a moment today to reflect on what we’ve achieved together during the past three years,” said Steve Jobs, Apple’s CEO. “Over one billion songs have now been legally purchased and downloaded around the globe, representing a major force against music piracy and the future of music distribution as we move from CDs to the Internet.”