Should we Use rel=canonical in ccTLDs websites

[CyrilWilson]

We have multilingual eCommerce websites with some content variations but majority of the content remains the same

We have used rel=alternate hreflang on corresponding ccTLDs respective countries. for example on example.com -which is the oldest of these sites- we have used

Now should we also use link rel="canonical" href="example.com" on all ccTLDs?

What are the advantages and disadvantages of using it?

[mrdavidingram]

Hi Cyril.

Google released a webmaster blog post that covers this specific instance quite extensively:

http://googlewebmastercentral.blogspot.co.uk/2010/03/working-with-multi-regional-websites.html

But in summary; yes if the content is going to be largely the same then I'd suggest using the canonical tag to identify the .com as the original source. The advantage of this is you wont fall into any duplication issues within Googles algorithm, the disadvantage being that the sites containing the canonical tag may struggle to build up their own authority as you are essentially telling Google that the content is not their own, so some of the link juice should be credited elsewhere.

Have a read of the webmaster article, they go into a lot of detail about the issue which will hopefully guide your path.

Good luck.

David

[CyrilWilson]

Thanks for the response David.Can you suggest what should one do if trying to make each site an authority in their respective country and not depend on the original version of the site.

How much content replication is duplicate content- any percentage, ratio defined by google?

[mrdavidingram]

Hi Cyril,

I've not seen any specific case studies or statements that figure out how much replication is considered duplication, although I'd be as interested in you in this information if anyone out there knows of some?

Personally, I have been working on a 50% minimum basis (e.g at least 50% of the pages written content should be unique), and it's been working well for me.

You might get away with less.

In regards to making sites an authority within their specific countries, whilst using duplicate content and the canonical tag, it's all down to links. Even though you're telling Google that this isn't the original source of the content, it's still possible to build up authority on the domain by acquiring links from strong sites that share the TLD.

But again, without unique content you're not going to see the full strength of these links.

David