Do sites on the same c-block and same server count as seperate linking root domains when linking to each other?

[cinternicola]

Lets say there are 50 businesses who have their website on the same server and are on the same c-block but the owners of the individual sites are different (i.e. they are all completely different sites not relevant to each other). Each of those sites are linking to each other due to a feature on the sites. This obviously increases the number of total links to each site but does it also increase the number of linking root domains? Or does this just show up as one linking root domain due to all of them being on the same server and the sharing the same c-block?

[RyanKent]

Do sites on the same c-block and same server count as seperate linking root domains when linking to each other?

Google will  can discount the links because they are all on the same server and C-block. Google views links as an independent endorsement of the target site. When links are created by sites on the same server, it is deemed likely there is a relationship between the sites which causes the links to not be independent.

Does this just show up as one linking root domain due to all of them being on the same server and the sharing the same c-block?

These would show up as separate linking root domains in the SEOmoz tools. If you are using other tools you would need to ask with the tool's developer to be certain, but all the tools I have worked with would show these as independent domains, which is true regardless of that domain's IP address or server.

[seoug_2005]

**Google will discount the links because they are all on the same server and C-block. **

Has there been any word on this officialy  from Google ?

[RyanKent]

Hi Atul.

Based on your question I have spent some time trying to locate an official reply from Google on this topic. I was not able to find such a statement. Therefore, I modified my reply from "Google will discount links (from the same C-block)..." to "Google can discount..."

What we know for certain is Google is a very intelligent organization and they have entire teams dedicated to ensuring search quality is maintained. Google specifically wants to ensure links are independent in nature. Links from the same C-block is clearly an indicator the link may have been influenced and is not independent.

I would even go further and share it is common belief amongst SEO professionals that C-blocks affect links. The entire concept of "SEO hosting" is based upon offering hosting with different C blocks.

A great white board friday discussion on this topic: http://www.seomoz.org/blog/which-link-metrics-should-i-use-part-1-of-2-whiteboard-friday

Rand shared in the above video "the best single metric, non-aggregated metric, that we've got to predict Google's rankings with correlation data is the number of Linking C-Blocks."

TL;DR - There is strong evidence which indicates C-blocks information is used as a ranking factor, but I was unable to locate any specific statement from Google confirming this information.