It's from your own source buddy (pretty intelligent of you, just search Zune on wikipedia)... 4% of the overall MP3 market (which is HUGE because a lot of people buy the cheap ones, some as cheap as $20)
The 11% is from the hard drive market (5/2007, which seem to be the last time hard numbers from the source were released), which are the legit, more expensive MP3 players
didn't use wiki.