For technical reasons, our dev agency have suggested that we publish all content to two different sub-domains, and have a canonical tag pointing at the original version. One of the sub-domains will be local (eg uk.domain.com), and about ten percent of pages will differ between the two domains (ie they will be localised). As I said, this approach has been for technical reasons (which I won't go into for fear of an essay), however I'm somewhat concerned about the idea of having the vast majority of our content published twice. Will we get slapped down in Google for duplicating our content (we're using canonical tags)? There's also the fact that we've basically got two sites now, meaning that our inbound links will be split (ie some links will go to uk.domain.com, and some will go to www.domain.com). Purely from a search point of view, what are your thoughts on this process? Thanks in advance for any replies.
I think the best way to keep the inbound links on your main domain is to use permanent redirects to your 'www' website. About the canonical: A canonical page is the preferred version of a set of pages with, in this case, similar Content. Google should only index those pages that you have selected to be the preferred version. So those pages shouldnt be treated as duplicates.