After reading: http://webtips.dan.info/brand-x/useragent.html, its clear that the web-browser shares are not 100% accurate… rather they cannot be 100% accurate.

Also see: http://virtuelvis.com/archives/2003/02/properly-measuring-msie (a little old, however could still be relevant)

So how accurate are http://en.wikipedia.org/wiki/Usage_share_of_web_browsers and other “browser usage reports”?