A site I am working with has multiple duplicate content issues.

[SkiBum]

A reasonably large ecommerce site I am working with has multiple duplicate content issues.

On 4 or 5 keyword domains related to site content  the owners simply duplicated the home page with category links pushing visitors to the category pages of the main site.

There was no canonical URL instruction, so have set preferred url via webmaster tools but now need to code this into the website itself.

For a reasonably large ecommerce site, how would you approach that particular nest of troubles.  That's even before we get to grips with the on page duplication and wrong keywords!

[EGOL]

I would see how much human traffic is coming into those satellite sites.  If very little I would redirect them to main site.  Then I would place all of my efforts into the main site.

The owners might not like that recommendation because they thought making the satellite sites was a kickass idea.  But if you show they are producing zero traffic or that the traffic bounces off of main site then the sale will be much easier.

[SkiBum]

Thanks EGOL, that's in line with what I thought.  One of them does produce a small flow of visitors.  My inclination is to recommend editing the content on that satellite to reflect its keyword and only link in to the couple of relevant sub categories at the main site.  All other non relevant content would be removed

The others I would redirect to the appropriate internal page of the website.

All the best and thanks again.