Exactly. Also, Apple's entire product line is on one page (+ the various configurations, of course) whereas Amazon sells hundreds of thousands if not millions of products on its own and through its affiliates. Apple also sells other products, but even then, the numbers can't add up to more than a thousand or two.
When all that is taken into account, being #5 is truly amazing.
Apple.com sells more than their product lines. Not comparable to amazon, but its not JUST mac/ipod. I would even venture to say they sell more non-mac/ipod product than the latter.