[gwillen]

If you follow the history of Wikipedia, ads have been discussed many times. The consensus has always been "no, absolutely not."

If the WMF put even a single ad on Wikipedia as an experiment, there would be a community uproar and probably at least one fork (much as the Spanish Wikipedia forked years ago under threat of ads, and didn't rejoin for years, even though the ads themselves did not persist.)

Personally, I think that's as it should be.