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.