In a new video on YouTube, Google’s Matt Cutts addresses duplicate content. He says that 25-30% of the content on the Internet is duplicate content.
According to Matt Cutts, that’s okay. Google doesn’t treat duplicate content as spam. Google does, however, show only one of the pages with the duplicate content in the search results. This might feel like a penalty but it’s not.
Google picks the best of the pages with the duplicate content and shows that page in the search results. You can view the video here: