Wikipedia has 2.25 million English Language articles. About 1.5 million are spam or “stub” articles, meaning they have a title and a few words, plus massive internal links. Here is an article about a quack doctor who has a web site hawking a book. The article explains that healthy food can kill you by means of starvation.
I’ve mentioned this as early as a year ago – for profit Wikia has until recently hosted a sexual fetish site devoted to spanking. (I would link to my old site on the issue, but the WordPress database is lost.) While links to references backing up Wikipedia’s claims were struck with a nofollow, links going out to the for profit Wikia community are given coveted PageRank with search engine friendly links. (This would be a good time to mention PR means almsot nothing except to lemmings – but there are millions of lemmings in the world.)
I applaud Wikipedia for helping people with special needs, but I question their motives.