Nobody knows, because the unknown factor in such calculations is whether Google would continue to bless Wikipedia so heavily if it started running ads. You cannot assume that the current dominance in search ranking would be maintained. Google can - and does - tweak algorithmic factors, which then have profound effects on what types of sites rank highly. If you seriously want to make a reasonable estimate, take a look at the closest similar types of sites which are commercial - e.g. about.com, answers.com, Weblogs Inc., Mahalo.com, Gawker (sorry!), etc. That would give a ballpark figure in terms of current Google practice. Skip the feel-good stuff about the community only being willing to do free work for an unsullied cause. The veritable Co-Founder Himself has a $14 million dollar venture-capital backed endeavor (Wikia) based on the theory that such an idea is false. Are you calling him and his marquee investors stupid? :-) In fact, Wikia's relative lack of profitability (it may be slightly profitable, but it's certainly not a money machine) is a pretty good indication that such monetization is quite difficult. Even with all the marketing and public relations advantages that Wikia gains via a "halo effect" from Wikipedia's prominence, it still doesn't rake in big bucks. So slapping a Google Ads box on many pages doesn't print money. Given the risk that it could actually kill the goose that lays golden "SERPs", err, eggs, it won't happen. -- Seth Finkelstein Consulting Programmer http://sethf.com Infothought blog - http://sethf.com/infothought/blog/ Interview: http://sethf.com/essays/major/greplaw-interview.php