in september 2007 I ran into duplicate content with my 2 domains, one www.mydomain.com and another one www.my-domain.com (with a slash). Until than the first domain ranked very well for its main keyword and combinations.
Before the problem occurred a site:mydomain.com would show all the URLs there were. After the problem occurred the same URL paths would suddenly show up under the second domain and a site:mydomain.com would return only a few results.
After discussing the problem here on webmasterworld, tedster confirmed that this is most likely a DC issue. So I installed a redirect 301 on the my-domain.com and as a result could observer how it took about half a year until a site:my-domain.com would return 0 results.
Today a site:my-domain.com still returns 0 results, but a site:mydomain.com only returns 27 pages all of which belong to my linkpartner area. All the other sites (about 40 000) do not show up anymore.
So at one point I added a sitemap, because I hoped that would anything. Well, I was wrong. Wonder why people use it?! Google read it and I have the following statistics:
Submitted Last time read Status URLS
27.02.2008 04.04.2008 OK 40060
If I click on Details I get the number of indexed URLs, which amounts to 37. All those URLs are linkpartner pages.
The only real difference between the URLs which are being indexed and are not, is that they have different extensions. The linkpartner pages have a .php extension, because I'm using a third party software. The ones not being indexed have no extension. Could that be the reason?
What else could be the reason that google ignores the rest of the site? Has anybody ever experienced similar symptoms?