The question is, will the backlink be natural. I believe that subdomains are still considered a seperate domain, however, according to what I read from Matt Cutt's, the change is in the philosophy, if a domain has a good reason to get a SERP based on relavence, they are pruning the results for that domain.

My logic, though very fallible, would be to explore

worpress.com

and

about.com

If you can do a site: command on a sub-domain, I think it's still considered it's own domain as long as it's content is VERY different from the main domain.

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