While it is clear that the age of a domain is part of a page's rank discussion, I have not yet seen clear consensus if that advantage is also passed on to its subdomains. So far, I was of the impression that this not happens, so if you start with a new site, it would not gain anything from a long-existing domain. Now, I made the experience that two of my brand-new sites do quite well. I begin to assume it has to do with the age of their top-level domain. I've some more details in my blog post Domain Age Advantage: does it spread to Subdomains? I need to add that my sites are in a non-competitive niche, so this may be the reason. Has anyone a (samewhat) solid thought in this? Thanks, Rainer