Google has expanded its Google Social Search results. If you're active in contributing content about your target markets on social media, it will influence your search rankings more directly.
Your activity on Twitter, Flickr and elsewhere — but for now, not Facebook — will be a lot more visible in Google’s search results, including having an impact on how pages rank.
One sutble but big change is that when you tweet a link to an article, for instance, about doctors and money, Google's search ranking until now were not infuenced if you did not actualluy create the content you tweeted. Now, however, even if yo did not create the content about doctors and money and simply tweeted about it, it will influence you seach ranking.