I think it is important to note however that Facebook like and Google +1 counts are becoming ranking factors but at the same time are also becoming huge influencers of click thru rate. Google is attempting to show you people in your social circle that like or have tweeted or +1ed a specific page directly in the search results. That would make me want to click something more.

Also, the social ranking factors aren’t as simple as counts, Google has come up with ways to give an authority value to different types of shares such as tweets. For example, Tweets from someone with 400 followers are going to carry more weight than tweets from people with less than 10 followers.