Are you worried about search engines like Google slapping a duplicate content penalty on your blog? Did you know that your blog posts can be accessed through multiple URLs which Google can consider as duplicate pages? Why not give them a subtle advise on which are your favorite URLs to get your content indexed?
For example, check this URL for this blog post:
Now someone may link to this post with his affiliate URL:
And if Google discovers both the pages, they will think we have duplicate content here and at will, index one URL and ignore the other.
Webmasters and blog owners have been stuck with this issue for long. However the big 3 search engines (Google, Yahoo and MSN) recently agreed on the specs for a special meta-tag that will help them them identify the real URL. You can specify this in the head section (I shortened the URL to fit the window):
<link rel="canonical" href="http://www.rentablogger...on-blogs/" />
This is a message to the search engine that we prefer to get this page listed under this URL. Please note that you are not ordering them to do so. They may act otherwise if they see a large number of places linking otherwise. Also you cannot point the engines to URLs under a different domain.
You can get a simple plugin to tackle the canonical URL problem here (courtesy – Joost de Valk)