Rather than comparing a convenient online copy of Wikipedia to a paper copy of Britannica ->0 of their readers have access to, or a deliberately-annoying Britannica website (see http://lists.wikimedia.org/pipermail/foundation-l/2008-December/048231.html and thread), they compared it to the other answers sites on the net, most of which are collaborative.
http://online.wsj.com/article/SB122981801892624313.html?mod=googlenews_wsj
- d.