Does a subdomain benefit from being on a high authority domain?

[RG_SEO]

I think the title sums up the question, but does a new subdomain get any ranking benefits from being on a pre-existing high authority domain. Or does the new subdomain have to fend for itself in the SERPs?

[RG_SEO]

Thanks for the help Ryan

[RyanPurkey]

Rand recently did a whiteboard Friday on this very thing: http://a-moz.groupbuyseo.org/blog/subdomains-vs-subfolders-rel-canonical-vs-301-how-to-structure-links-optimally-for-seo-whiteboard-friday, the pertinent part on your question being:

You're asking, "Should I put my content on a subdomain, or should I put it in a subfolder?" Subdomains can be kind of interesting sometimes because there's a lot less technical hurdles a lot of the time. You don't need to get your engineering staff or development staff involved in putting those on there. From a technical operations perspective, some things might be easier, but from an SEO perspective this can be very dangerous. I'll show you what I mean.

So let's say you've got blog.yoursite.com or you've got www.yoursite.com/blog. Now engines may indeed consider content that's on this separate subdomain to be the same as the content that's on here, and so all of the links, all of the user and usage data signals, all of the ranking signals as an entirety that point here may benefit this site as well as benefiting this subdomain. The keyword there is "may."

I can't tell you how many times we've seen and we've actually tested ourselves by first putting content on a subdomain and then moving it back over to the main domain with Moz. We've done that three times over that past two years. Each time we've seen a considerable boost in rankings and in search traffic, both long tail and head of the demand curve to these, and we're not alone. Many others have seen it, particularly in the startup world, where it's very popular to put blog.yourwebsite.com, and then eventually people move it over to a subfolder, and they see ranking benefits.

If at all possible, make it part of the domain in a subfolder.