IPod's Law: The Impossible Is Possible - New York Times

"APPLE says its iPod music player and iTunes music store have 74 and 85 percent of their worldwide markets. But according to Gene Munster, a Piper Jaffray analyst, the end is near. 'Nobody can sustain an 80 percent market share in a consumer electronics business for more than two or three years,' Mr. Munster told CNN. 'It's pretty much impossible.' "