Nice tools for Webmaster : Google Sitemaps
As Matt explains in his Video Session 13 : Google Webmaster Tools, a use of Google Sitemaps with Webmaster help Center is quite useful.
The new feature : Preferred domain setting is truely wonderful tool, and I am eager to see Serp when the URLs unified. (Matt says it may take weeks)
On the other hand, there you may have further thoughs about URLs, which have same content but indexed by Google as different pages. In any case, if Search Engines indexed variable URLs of your site, it is recommended to manage the accessible URLs into one URL using 301 redirect y/or mod_rewrite : defining your official site URL.
Because Preferred Domain setup feature is for Google index, and not work with Yahoo’s index.
As simple handling, if someone reached to your site by http://yoursite.com when your official URL you set up is http://www.yoursite.com and if there is no redirect, she/he may bookmark “http://yoursite.com” or put the link from her/his website.
If her/his website has a high score qualification by Google, backlink vote to your site would be pointed to “http://yoursite.com” instead of “http://www.yoursite.com”.
In order to avoid such case, better use mod_rewrite.
Pages where “mod_rewrite” (.htaccess) is topic :
FAQ: mod_rewrite, 301 redirects, and optimizing Apache.
Stoping a .htacess file from applying to sub-directories?
Related pages in Google Webmaster Help Center :
URLs not followed /Redirect URL too long
Why does my site have two different listings in Google: http://site.com and http://www.site.com?
Same content but different URL issue has many angle.
http://www.yoursite.com vs http://yoursite.com
http://www.yoursite.com/ vs http://www.yoursite.com/index.php
http://www.yoursite.com/subdomain/ vs http://subdomain.yoursite.com
…
A very beginner confusion is to think :
http://www.yoursite.com/ = http://www.yoursite.com/index.php
But, this is not correct.
http://www.yoursite.com/ is not seen same as http://www.yoursite.com/index.php by Google or other search engines.
If you are using back to home internal link in your site, better check which URL you use and if you see various URLs, I suggest you to unify it.
Hot to check it quickly ?
Put the URL in search box of Search Engine, and you see whether the URL is indexed or not in Search Engines. Then, check back to home links within your sites.
