Analysis carried out by the independent research and consulting provider Generator shows that Apple's music business could more than double the size of the company in just five years. For the year ending September 2002, music contributed only 2.6 percent to Apple's total revenues. By September 2005, however, music had grown to account for 40 percent of revenues and by September this year, Apple will be deriving most of its revenue from music, rather than iMacs. "Most people now understand that Apple's music business is the main source of growth but what's not widely appreciated is just how big the music business could become in the future. It's a big worry for some people in the industry," said Andrew Sheehy, Vice President of Research at Generator.

The iPod range, sales of which exceeded that of Sony Ericsson in Q4 of 2005, will remain the primary source of growth, although the iTunes Music Store will be contributing 37 percent of total music revenues by 2010. The revenue projection excludes several important factors, all of which have the potential to increase company revenues still further.

"We have excluded revenues from non-music content categories such as TV shows and movies and new device categories, such as a new Apple product line aimed at the home entertainment market which would compete with products that are based on Microsoft's Media Center PC," Sheehy said.