Before we begin, you might want to watch this short video on what Google +1 is exactly.
Perhaps one of the most interesting things about Google’s +1 button is that it will actually affect search engine rankings according to Google’s David Byttow. As the web evolves, Google has to use more and more social signals as indicators of which web pages are most relevant to the user. With the amount of link spam increasing by the day and the methods of link spamming becoming increasingly complex, Google and other major search engines are being forced into using external factors to calculate search engine rankings.
What also makes +1 powerful is that when people within your social circle are signed in, they will see your recommendations if they perform a similar search. One of the key differences between the +1 system and the former Google search wiki is that users are no longer able to annotate listings. Most likely a result of the many slanderous remarks some websites had previously received.
Moving beyond just search, Google +1 can also be placed directly on web pages for users to vote right on the site. Already Google has taken a step forward and allows webmasters to see insights on their +1 statistics by using Google Webmaster Tools.