On December 04, 2009 Google announced that they will design and customize your search results based on your past search activity even if you are not signed in your Google account. What it means is, the search results you see on your computer may differ slightly from what someone else might see on their computer. Google is now keeping track of your search history from the last 180 days on your browser’s cookies and produce the search results based on your search behavior. You can learn more about this feature on Google’s official blog
This is an important piece of information for all web designers, web developers, website owners and SEO professionals who monitor their website rankings on Google. You will see a difference in search rankings dependent on what computer you are searching on. In order to see the global search results, you can simply turn off this feature from Web History which is shown on top right corner of Google.com. This will tell Google that you do not wish to customize the search results based on search activities performed on that computer.
