Barry Ritholz, a professional money manager, just posted an insightful blog that reviews
11 years of the iPod . It's filled with data about the devices, including the fact that 350 million have been sold, and that Apple's share of the MP3 player market last year was 78 percent. The problem comes when you look at the data on the iPod as a share of Apple's revenue. When the iPod launched in 2006, it was responsible for over 40 percent of Apple's revenue. Then the iPhone was launched the following year, and the iPad in 2010. This year iPods contribute less then 5 percent of Apple's revenue.