Should I redirect all my subdomains to a single unique subdomain to eliminate duplicate content?

[DuProprio.com]

Hi there!

I've been working on http://duproprio.com for a couple of years now.

In the early stages of the website, we've put into place a subdomain wildcard, that allowed us to create urls like this on the fly :

http://{some-city}.duproprio.com

This brought us instantly a lot of success in terms of traffic due to the cities being great search keywords.

But now, business has grown, and as we all know, duplicate content is the devil so I've been playing with the idea of killing (redirecting) all those urls to their equivalent on the root domain. http://some-city.duproprio.com/some-listing-1234 would redirect to equivalent page at : http://duproprio.com/some-listing-1234

Even if my redirections are 301 permanent, there will be some juice lost for each link redirected that are actually pointing to my old subdomains

This would also imply to redirect http://www.duproprio.com to http://duproprio.com. Which is probably the part I'm most anxious about since the incoming links are almost 50/50 between those 2 subdomains...

Bringing everything back into a single subdomain is the thing to do in order to get all my seo juice together, this part is obvious... But what can I do to make sure that I don't end up actually losing traffic instead of gaining authority?

Can you help me get the confidence I need to make this "move" without risking to lose tons of traffic?

Thanks a big lot!

[DuProprio.com]

Hi Matthew,

I think your suggestion is great, as it would instruct google of the fact that I'm aware I have duplicate content, and want to tell him which one should be prioritized. However there are other aspects that would not be fixed in terms of seo that I'd like to get fixed with this "project"

If I keep all versions active with this canonical tag, I'm still spreading my incoming link juice through different subdomains, thus minimizing my potential domain authority...

For this reason I'm still thinking of making the real big & bold move... which is still giving me goosebumps!

[MatthewBarby]

I think one of the best resolutions to this problem would be that instead of just redirecting everything is to just add canonical tags to the duplicated pages that then point to the page with the original content on.

This will tell Google that the webpage contains information that is taken from another page and you wont be punished for this.

For example, on the http://duproprio.com/some-listing-1234 page, the canonical tag would link to the http://some-city.duproprio.com/some-listing-1234 page (or vice-versa depending on which page is the priority). So the code would be:

href="http://some-city.duproprio.com/some-listing-1234 page" rel="canonical"/>

Hope this helps.

Matt.