Since the days of Google Buzz, the +1 button has been a mystery to users and content producers alike. It’s different from Facebook’s “Like” button, in that it doesn’t directly share content to a user’s social stream. But the cultivation of a social graph has long been the goal of Google, and its connection to search was likely inevitable.  Google defines the +1 as a feature to help people discover and share relevant content from the people they already know and trust. Users can +1 different types of content, including Google search results, websites, and advertisements. Once users +1 a piece of content, it can be seen on the +1 tab in their Google+ profile, in Google search results, and on websites with a +1 button.  The plot thickened last month when Google launched Search plus Your World. Jack Menzel, director of product management for Google Search, explained that now Google+ users would be able to “search across information that is private and only shared to you, not just the public web.” According to Ian Lurie from the blog Conversation Marketing, in Search plus Your World, search results that received a lot of +1s tend to show up higher in results.  Google has come out and described the purpose of a +1, but hasn’t necessarily explained the direct effect a +1 has on search ranking. Here’s a breakdown of what we currently know.  The +1 has an indirect effect on your site’s search rank. This does not mean the more +1’s a link has, the higher rank it achieves in traditional search results. Take this scenario:  When a Google+ user +1’s a piece of content, he gives it his “stamp of approval.” Then, say one of his connections from Google+ searches for the same or related topic. Because of Search plus Your World, his friend is more likely to click on the same link the original user +1’d (when a signed-in user searches, his Google results may include snippets annotated with the names of connections who have +1′d the content). This is because content recommended by friends and acquaintances is often more relevant than content from strangers, according to Google.  This is also true for users who are not signed in to their Google account when they search. When a user searches for the same phrase, the results might display the total number of +1’s a link has received, which is another validation that it’s a relevant link.  Since the +1′d link has a chance at a higher Click-Through-Rate (CTR), there is a greater potential the link will be shared, whether it be on Facebook, Twitter, Google+, or any social network. An experiment by Rand Fishkin, CEO and co-founder of SEOmoz, tested the relationship between Twitter and Facebook shares and search results in Google. He found a positive correlation between the number of retweets and shares a link received and its search ranking. This means, the more the link was passed around on Twitter and Facebook, the higher the search rank of the page. This in turn led to better SEO.  A Google +1 can indirectly lead to a better page rank. A greater number of +1’s increases a link’s potential for a high CTR, which could lead to increased social sharing, and in turn can increase its Google search rank. What’s important to note here is the correlation, not causation, between +1′s, other social shares, and search rank.  The bottom line is, the SEO effects of a +1 are very indirect, which means traditional SEO practices should not be ignored. SEO methods such as link building, relevant keywords, and URL structure have a more significant impact on page ranking.  The Google +1 feature is still in its infancy of course, and more data needs to be gathered to draw a statistical correlation to search. As Google said, “For +1′s, as with any new ranking signal, we are starting carefully and learning how those signals affect search quality.”  SEO experts, such as Erin Everhart from 352 Media Group, have a positive outlook on the future of social search. She says, “I don’t think we live in a world, nor will we ever live in a world, where any social cue doesn’t have influence over SEO.”  Are you seeing the effects of Google +1 on your SEO? Will the +1 eventually have a direct effect on search rank? Share your experiences in the comments.
Google's +1 button doesn't share content to the stream the way the Facebook "Like" does, but there must be a connection to search. Here's what we know so far.