http://news.bbc.co.uk/1/hi/entertainment/7428104.stm
"Q: If Wikipedia can stay free of advertising why can't the BBC? The worst decision the Trust has made, in my view."
(I must note that I personally don't object to ads on Wikipedia, but I do think it would be a public relations disaster externally as well as internally, and should be avoided as hard as we can. I'm posting the above for anecdotal interest.)
- d.