I have read this article: http://www.mattcutts.com/blog/subdomains-and-subdirectories/

But I'm not 100% clear if moving my subdomain website into a subdirectory on the main domain would change anything related to SEO.

I inherited this structure:

  1. Informational site related to our specific industry lives at: http://example.com
  2. StoreFront where we sell product related to our industry lives at: http://store.example.com

The informational site gives a lot of good information on how to use the products we sell. The storefront is primarily used for the ecommerce function of selling the products, but there is a lot of info specific to the products on that site.

Question: Is our main domain http://example.com getting page rank credit for the product info contained at http://store.example.com? Would there be a benefit to changing the structure?


1 Answer 1


PageRank (one word) is per page, not per site. It is only a numerical representation of a page's link popularity. So as far as PageRank is concerned there is no concept of subdomains and websites. Just individual pages. So if you want to have any PageRank associated with your store "passed to" pages on your main website you need to link to your main website's pages from your store's pages. Links are how PageRank is "spread". You can read about the PageRank formula at Wikipedia as it is public knowledge.

The Matt Cutts article pretty much states that as far as SEO is concerned that there is no difference between subdirectories and subdomains. So based on your question there is no SEO benefit to moving your subdomain to a subdirectory.

  • Thanks that's helpful. More generic question, I've read that all pages within the domain increase the credibility of the primary domain as a whole. (Ex: domain.com/index.htm benefits from all other pages at domain.com). If true, would the info contained in the sub.domain.com feed into the credibility of the primary domain.com/index.htm without direct inter-linking? Or is this idea of credibility feeding back to the primary domain from its pages not real?
    – JMC
    Mar 11, 2011 at 16:28
  • @JMC That "credibility" thing is speculation and even then definition varies widely. If there is a credibility thing it affects spam control more then it does ranking. And even then, if there is such a thing as credibility, since there is no SEO difference between subdirs and subdomains then it still works out the same.
    – John Conde
    Mar 11, 2011 at 16:31

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