Things to watch for:
GET parameters in the ULR
- session ids
- form fills
- eCommerce properties
These all will create a URL with extra data that makes Google think that there are multiple unique page URLs with the same content which means duplicate content. GROSS. So make sure you take your time and resolve this issue using canonical URLS.
<link rel="canonical" href="http://www.rolledalloys.com/"/>
Meta Tags Robots.txt
Google Web Master Tools preferred Domain
It’s possible that the US version will outperform the Canadian version (even on Google.ca) because it has more authority.
There’s a simple solution: the rel=”alternate” hreflang=”x” annotation.
If we use our previous example, we need to add the following code in the <head> section of the .us domain:
<link rel="alternate" hreflang="en-CA" href="http://company.ca/page-example" />
On the .ca domain we need to place this code:
<link rel="alternate" hreflang="en-US" href="http://company.com/page-example" />
In essence you’re telling Google that there’s an alternative version (or duplicate) in another language.