Several years ago, during a site redesign, I created copies of some pages on the site. At the time I did not want to delete the old pages because they were well established with many pages linking in. I figured the easiest thing to do was to just leave the old pages. It has now come to my attention that search engines penalize duplicate content. What should I do with the duplicate pages to maximize the ranking of the pages in question? I have considered using 301 redirects, but do not want to lose ranking. If I do choose to do a redirect, does it matter if I direct the higher ranking page to the lower ranking one, or the lower ranking one to the higher? After our host mistakenly deleted our files, we created what amounts to a mirror of our site with a .uk extension. How does this effect ranking? Is there a way to inform the search engines that the other site is a mirror and is not 'bad' duplicate content?
Duplicate content is very common on the web. It comes in the forms of content syndication, mirror sites, content scraping, quoting, reusing content, data fed sites etc.
Thanks for the replies. I suppose that my question really has more to do with optimizing 301 redirects, because the duplicate content only appears on different pages on our site. I would also be interested in learning about other options other than 301 redirects.
You can do 301 redirects or use the canonical tag to point to the new URL. http://googlewebmastercentral.blogspot.com/2009/02/specify-your-canonical.html
Thanks for the info about the canonical tag. I had not kept up with these things and was not aware of it. In terms of which page to redirect, I suppose that I should redirect the lower PR page, as this would leave the PR of the higher ranked page undiminished.
When you do a redirect the page rank of the page you are redirecting passes to the new page, it loses a little of the page rank (something like 80% of it passes along) but the rest of it passes to the new page. It is natural to experience a little dip in page rank when the redirect is first implemented, but once the search engines identify the redirect and index the page being redirected to, the page ranks should stabilize for the new page. Since the page rank is passed with the redirect it is ok to redirect a higher page rank page to a lower one (this is typically the case when you are redirecting an older page to a newer one). If you are concerned about not redirecting a higher page rank page then you can redirect the lower one, but this could create a scenario where some pages on site A have a higher page rank then their equivalent on site B and some pages on site B have a higher rank then their equivalent on site A. Then you would end up redirecting some pages from site A to site B and some pages from site B to site A which could get messy. Typically sites will redirect all pages from one site to another. I hope that was clear and makes sense.
Unique title, remove duplicate title, after that create page 404, use nofollow. I still do that to have content unique.