Understanding Google’s SEO Practices

Google wants to deliver value to people who use it’s search engine. For this topic, that means showing a diverse selection of results when you perform a search. No one would want to see the top 10 search results filled with exact copies of the same article. Google knows this and eliminates showing exact copies as well as extremely similar pages.

Google knows you want to see a good selection of pages that are relevant to your search and different enough from each other to be unique. This prevents webmasters from copying an entire site and reproducing all the content on other domains. Yes, believe it or not webmasters would try to game the system to get more traffic. Who knew?