Best practise linking between root and subdomains

[theskunk]

Hi,

MAY 1st TRAFFIC LOSS DUE TO PERCEIVED LINK SPAM CAUSED BY NORMAL SITEWIDE LINKING BETWEEN ROOT DOMAIN AND SUBDOMAIN (maybe:)

I run my commerce site in shop.domain.com I have various articles, content pages, and stuff on my root, maybe 300 pages. These pages link back to my home page and some other run of site pages, and categories in my shop.

Then I have pages like:

support.domain.com and
blog.domain.com

Which have the same kind of run of site links.

SINCE THE PENGUIN CAME TO TOWN

I have noticed a drop on May 1st 2012 So i checked WMT and can see that I have an extreme amount of backlinks to my shop.domain.com - LIKE AROUND 6'000'000 - It seems that the links dont even have to me

My MOST linked to page is teh world pay call back page - that I dont actually link to from anywhere other than the shop.domain.com - SO THIS SHOULD BE AN INTERNAL LINK.

BUT - in WMT is is being classed as a BACKLINK that somehow - uses what they call intermediate link. So a link from shop.domain.com to the worldpay call back is being classed as a BACKLINK from support.domain.com even though support.domain.com doent link to the WorldPay Call back page. HOW WEIRD IS THAT? Whatever is made my backlinks explode to unatural levels.

I guess this isnt good. IN reality these are internal links accorss my subdomains which in my mind is really one domain

HOW CAN I TELL GOOGLE TO TREAT ALL MY SUBS AS A SINGLE SITE

A bit like we use rel="canonical" for pages, I need one for subs domains.

Is that possible? Will it be BEST practise? Is is normal to have such large amounts of back links. My commerce site has around 70'000 product pages.

sorry i didnt spell check this.

IF ANYONE CAN ADVISE ME RE BEST PRACTISE ON THIS I WOULD BE VERY WELCOME - WMT WTF

[Andy Langton]

It's pretty normal to link sitewide to subdomains, so unless there are some other unusual factors, I think it's unlikely this in itself would cause Penguin (or other) problems.

That said, there's a clue to a problem in that backlink report - if it claims 6 million links, then Google must have picked up on 6 million URLs, which implies a big problem in terms of content that probably shouldn't be getting indexed.

I would suggest you either spider your shop site yourself with something like Xenu, or separately verify the subdomain in webmaster tools and check out the crawling data. But pinning down that 6 million number would be a worthwhile exercise.

[theskunk]

Interestingly as I suspected these subdomain links are considered a problem for the penguin saga.


<snip>

From WebProNews

The most perilous piece of WPMU's link profile came from one site - EDUblogs.org. EDU Blogs is a blogging service for people in the education space, allowing them to easily set up a subdomain blog on EDUblogs for their school-focused site - in a similar fashion to Blogspot, Typepad, or Tumblr, meaning that each subdomain is treated as a unique site in Google's eyes. Coincidentally, this site is owned by WPMU and Farmer, and every blog on the service leverages WPMU theme packs. Each of these blogs had the "Wordpress MU" anchor text in the footer, which meant a high volume of subdomains considered unique by Google all had sitewide "Wordpress MU" anchor text. In what might have been a lucky moment for WPMU, this portion of their external link profile was still completely in their control because of WPMU ownership.

In what I believe is the most critical reason why WPMU made a large recovery and also did it faster than almost everyone else, Farmer instantly shut off almost 15,000 'iffy' sitewide, footer LRDs to their profile, dramatically improving their anchor text ratios, sitewide link volume, and more. They were also able to do this early on in the month, quickly after the original update rolled out. A big difference between many people trying to "clean up their profile" and WPMU is time - getting everything down and adjusted properly meant that many people simply did not see recoveries at refresh 1.1 - but that doesn't mean it won't happen at all if the effort persists.

</snip>

Looking at my WMT back links report it seem like google has gone totally off target in its ability to calculate back links effectively. I am very concerned that they still show me as having 9'000'000 backlinks form my subdomains to my main domains.

Due to the size of my site I have been unable to get a tool that does not time out to effectively get all my back link info.

If there was such a thing as advice for how to get a clear picture of what is going on here it would be very welcome.

cheers,

Nic