I went to the wiki page yesterday for my keyword and when I looked closely I found one of my competitors has hidden their links quite well on the page. I already have one of my links on the page but it is well thought out and adds to the page (although maybe not totally within wiki's rules), something my competitors did not do. Their links have now all been edited out with the reason given being "blatant advertising spam". Yes - I did feel a bit guilty, but the guilt washed away five minutes ago when I overtook them in a lucrative G search. Maybe it's something we should all check.