Marketshare vs Installed Base - Roughly Drafted

I've been doing some reading from the links over on the Zune! Pffffff... (Hide-A-Pod link to Squirt Option section to "any users" link to a later RD article...) and came across this one. I hadn't paid enough attention to know that Apple is pulling over half the profits of MS. With just 2% global market share, and a pretty great brand name.