As of June 28, 2011, Google added the ability to "plus" a web site. This action will add the web site to your Google social networking profile so that your friends can view what sites or pages you like. Of course, I "plused" one of my own sites. Some time later, I used a search term I was targeting on Google to check my site's search result placement (SERP) and noticed that my web site jumped from page 4 to page 2 on Google. After some investigation, I found that the result only happened on a computer that I was logged into Google with. In fact, if I "plused" any site that linked to my website, the same change in placement occured. If I removed all the "plused" sites from my profile or logged off of Google, the search results were back to normal.
