For instance, if you are logged into Facebook, you can go to Bing and see what your Facebook friends like. On YouTube, or anywhere.
Google, in an attempt to face off with Bing, created its own social network called Google+. When you conduct a Google search, beside each search result you’ll see a +1 button. If you +1 an item and you set your preferences on Google+ just right, then your friends will be able to see what you plussed on your Google+ profile page, and you they.
But Google takes it another step further than that even. On the search results page, you can see what items your friends have shared on Google+ and you can see other items they have shared on any social network – including Facebook.
Are these social signals exhaustive? Not by any means. In fact, they are just the beginning.
Social search is in its infant stage. I believe social signals in search will become much more important and we are only getting started. It will be exciting to see where the search engines of the future will take us. I can hardly wait to get there.