Wikipedia, the wiki-based nonprofit online encyclopedia, may begin to carry advertising according to founder Jimmy Wales, who told Times Online (U.K.) that "at some point questions are going to be raised over the amount of money we are turning down." An ad-supported approach is likely to meet with serious resistance from "wikitopeans" (the volunteers who create entries). But Wales, himself a volunteer, said both he and they need to consider "how the charitable mission could be supported by money raised through advertising."

That mission is to provide a free online encyclopedia to everyone in the world in their own language.

Wikipedia is ideally suited for online advertising: It now receives around 2.5 billion pageviews per month, and traffic is doubling every four months. It was the ninth-fastest-growing website in 2005, according to Nielsen/Netratings.