I just wanted to update my previous post.
I had links in Wikipedia to pages on my site for about four years, until they were removed just months ago.
There's a competitor site whose link profile shows hundreds or even thousands of links from Wikipedia if I do a Google link: search.
Previously this competitor site didn't rank on the first page for any terms I target. Now I find that I'm outranked by this site for many terms.
I went back to Wikipedia and added my links again, only to have them removed immediately by an editor who labled them as spam. I contacted the editor to question why my links were removed, but the links to the competitor site were allowed to stay.
His explanation was that the competitor site was informational, while mine was clearly commercial. Horsefeathers. The competitor site is plastered with banner ads, as well as affiliate text links in the "content" pages. Further, my site offers useful information as well, and a minimum of advertising by comparison.
I find it hard to believe that a Russian site with tons of links from Wikipedia can now outrank many established US sites that don't have links from Wikipedia, and to believe that those Wiki links don't count.
I also wonder how the owner of the competitor site has obviously ingratiated himself with the editors at Wiki.