Effects of significant cross linking between subdomains

[helga73]

A client has noticed in recent months that their traffic from organic search has been declining, little by little.

They have a large ecommerce site with several different categories of product - each product type has its own subdomain. They have some big megamenus going on, and the end result is that if you look in their Webmaster Tools for one of their subdomains, under Links to your Site, it says they have nearly 22 million links from their own domain!

Client is wondering if this is what is causing the decline in traffic and wondering whether to change the whole structure of their site.

Interested to hear the thoughts of the community on this one!

[GPainter]

First thing I always do is pretend i don't work for the company etc. go to the site as a user and see how easy it is to navigate, can i find the product i need easily?(try to imagine you want a product prior to going on) Can i get back to the home page easily etc.   I try to make sure I can access my home page (or the main products) only 3 pages away (5 max).  Google won't index huge sites it just doesn't have time so if your structure is bad it may be Google bot giving up as it can't get all the way down to where you in fact want it to go.

If you find your self lost in "megamenus" imagine the user or Google bot, can you reduce the menus to achieve a good result?

Other factor could be the decline in traffic has there be a Decline in your placement in the SERP or seasonal traffic ?  Although not a permanent fix PPC can help top up traffic to your site whilst you jiggle it a bit.

I hope some of the questions above help you look at the site in a different light, there are obviously other things it could be but first off I would look into your SERP placement and seasonal dips. You can use GA to look at users drop off points see where they are getting bored or getting lost too!

Best of luck!

[helga73]

Hi Chris,

Thanks for your reply. The issue isn't that Google hasn't indexed those pages, though - it has. I'm not sure what you mean by 'Google won't index huge sites it just doesn't have time', as it clearly does index plenty of huge sites.The site is pretty much fully indexed so it's not that Google can't find the pages.

We have also, of course, tried using the client's Analytics to identify the issue, as you describe, but the client accidentally deleted all the historical data beyond about the six month mark (oops), so I can't do a lot of the analysis I would normally do. I have one or two odd old printouts showing some historical Analytics and ranking data, and their sales data to go on, and this does tend to suggest that organic traffic has indeed dropped off (for reasons other than seasonal ones) and that there has been some decline in their search engine rankings for some key phrases. But I can't tell a lot more than that.

What I'm looking for is to see whether anyone else has had experience of this or a similar issue - whether anyone has seen excessive links between subdomains have a negative impact on rankings & traffic. I've been working in SEO for ten years and never come across anyone who has quite this many links within their own website, so it's not something I've encountered before.

Anyone else out there come across this before?

[GPainter]

You mentioned it's a large site Google only goes so deep into a site but as its an irrelevant detail it doesn't matter. Have you tried blocking some of the unused pages by robots and/or implementing tags like canonical &/or pagination tag

http://googlewebmastercentral.blogspot.co.uk/2011/09/pagination-with-relnext-and-relprev.html

https://support.google.com/webmasters/answer/139394?hl=en

you could look in Google trends for a rough idea of search volume over the years but that wont help your site as you mentioned. you can try tracking your SERP rank in Moz or other sfotware like serpbook etc.

Sounds like you've dropped down in your SERP to me.

[Everett]

Helen,

I know people who have had success in reducing the number of links within mega menus by turning some of them (after the first two levels, for instance, but you could get much more sophisticated if you wanted) into javascript links. If the javascript is not too complex Google will still have no trouble getting to those pages, but the links won't be "hrefs" and therefore won't waste pagerank on pages that are not as important relative to the others. The upside to this is that the links are still there for users, assuming that is a good thing.

As someone else mentioned, consider whether having those links there really is good for the users, or if they'd rather see a simpler menu. The search engines are beside the point in that case.

Any time an eCommerce site experiences slow, steady traffic drops I always look into the uniqueness of their product copy. That is often a sign that they are sharing product copy with other sites, either due to manufacturer description use, or by publishing feeds to 3rd party sites like Amazon, eBay or price comparison shopping engines.

Good luck!