[RS]

"Thus you could have approximately the same number of Apple users/customers - but it wouldn't necessarily show in sales figures."

If these figures are anywhere near correct -

http://www.pegasus3d.com/total_share.html

if EVERY Apple/Macintosh computer ever sold were still in use today it would not get even close to the number of PC's sold last year alone.

[TheBattman]

According to that page, Apple sold 3.5 million Macs in 2004 -

Sounds like a number worth paying attention to from a developer's point of view.