Duplicate Content www vs. non-www and best practices

[EnvoyWeb]

I have a customer who had prior help on his website and I noticed a 301 redirect in his .htaccess

Rule for duplicate content removal : www.domain.com vs domain.com

RewriteCond %{HTTP_HOST} ^MY-CUSTOMER-SITE.com [NC]
RewriteRule (.*) http://www.MY-CUSTOMER-SITE.com/$1 [R=301,L,NC]

The result of this rule is that i type MY-CUSTOMER-SITE.com in the browser and it redirects to www.MY-CUSTOMER-SITE.com

I wonder if this is causing issues in SERPS.  If I have some inbound links pointing to www.MY-CUSTOMER-SITE.com and some pointing to MY-CUSTOMER-SITE.com, I would think that this rewrite isn't necessary as it would seem that Googlebot is smart enough to know that these aren't two sites.

-----Can you comment on whether this is a best practice for all domains?
-----I've run a report for backlinks.  If my thought is true that there are some pointing to www.www.MY-CUSTOMER-SITE.com and some to the www.MY-CUSTOMER-SITE.com, is there any value in addressing this?

[RebekahMay]

Ideally one version of the site should redirect to the other version using a 301 to transfer any link juice from one version of the domain to the other.  In an issue where both versions have links pointing to them, the best solution is to see which version has the highest domain authority and the most links and use that as your preferred domain.

[Oren.]

You want to commit to one and put a 301 on the other.  Googlebot should be smart enough, but it isn't really.  Some things aren't best to be left to chance.

Here's the Moz 301 redirect article: http://moz.com/learn/seo/redirection

Edit: Here's another article about www.mysite.com vs mysite.com http://www.stepforth.com/resources/web-marketing-knowledgebase/non-www-redirect/#.UlbGl1Cko2s

[RohitPalit]

-----Can you comment on whether this is a best practice for all domains?

Yes, it is.

-----I've run a report for backlinks.  If my thought is true that there are some pointing to www.www.MY-CUSTOMER-SITE.com and some to the www.MY-CUSTOMER-SITE.com, is there any value in addressing this?

You shouldn't worry about that at all. 301's are just fine. They don't only redirect visitors, search engines like Google also follow them to pass authority signals to the redirected page.

[ThompsonPaul]

_If I have some inbound links pointing to www.MY-CUSTOMER-SITE.com and some pointing to MY-CUSTOMER-SITE.com, I would think that this rewrite isn't necessary as it would seem that Googlebot is smart enough to know that these aren't two sites. _

Absolutely NOT, unfortunately. Search engines specifically consider these two versions of the URLS to be two totally different sites. The redirect rule you currently have is specifically in place to correct this problem so the two versions of your site (in the eyes of the engines) aren't competing with each other.

The previous developer knew what he was doing. Leave the redirect as-is. Just be careful that all links you create use the primary version of the URL - you'll retain a bit more "link juice" that way than having them go through the redirect. (i.e. always write links as www.my-customer-site.com/whatever for links in content, menus, incoming links where possible)

Paul

P.S. For proof that search engines consider those URLs different sites, Google's own Webmaster Tools has a setting where you can tell Google which version of the site URL you want to be primary. Much better to do this with a proper 301-redirect though so that you can tell ALL search engines, not just Google.