I just searched for the term "buy viagra" (no, I'm not into that, but I know it's a highly competitive term and I was curious to see what are the sites ranking on the first page for that), and much to my surprise I noticed that 7 out of the first 10 results are forum profiles (the eight one is a profile on viddler.com, a video sharing site/social network). What's even more curious is that those people have 0 posts on the respective forums, and most (if not all) of these profiles were created this month. Can anyone explain how come these newly created profiles with 0 posts can be on the first page of Google for such a competitive keyword (19,500,000 total results)???
Viagra sites all the time are getting banned by Google, most use shady techniques. Viagra sellers don't want to wait out their 6 month sandbox time on building a new domain only to promote it, too much of an investment for them. These profiles they make lets them sidestep sandbox, they assume the credibility off the domain the profile is hosted on. As far as google knows ... they see an established, credible website suddenly has a page on Viagra, they're certainly going to give that better treatment than a brand new website. It also allows them to spam low quality links to the page. I believe Google knows what spammed links are, and if all a website has is spammed low quality links ... thats not going to do the site any good. However, if a site has mostly good quality links to it, yet a few spammed links, Google gives those spammed links the benefit of the doubt, because its to a credible website. So they can spam on a page that looks like this http://teamsystemrocks.com/media/p/36490.aspx to a brand new viagra website in a sandbox and they get nowhere. But if they post a link on that page to a credible website, Google gives it more weight (because the ratio of credible links to bad links is still very positive for the credible forum profile site). Hopefully, eventually Google will fingerprint the most commonly used profile-style pages and factor into their algorithm not to rank them so highly.
It is a known black hat technique. Basically they use another website trust and than link spam it and use other techniques to rank the profile as if it was a website. Most of this guys have some programming knowledge and automate most of the process, so by the time google deindex the profile they already have another 1000 ready.