I just checked my Google Webmaster Tools account and noticed “+1 Metrics” for the first time. I’m sure you’re already aware of Google’s most recent venture into social media called “+1″, which is pretty much the same thing as a Facebook Like button. Over time, the site that has more +1 votes will surely outrank other websites that do not have any +1 votes. I wouldn’t be surprised if these social media factors, including Google’s +1, Facebook Likes, Twitter ReTweets, Stumbles from StumbleUpon, Upvotes on Reddit, Diggs on Digg, and so on end up replacing the importance of simple backlinks from other websites, which is the lifeblood of Google’s algorithm and PageRank formula. Obviously, Google knows that backlinks can easily be spammed to manipulate the rankings, so putting more weight on actual “trust” factors from actual humans voting that they like a particular page will aim to solve that problem. However, I can see an entire new industry propping up offering services to vote up your site just as there are tons of linkbuilding services around today. It’s basically the neverending game of cat and mouse so it will be interesting to see how this all plays out!