Recently my friend Cyrus Shepard created a bit of a firestorm in the SEO world when he published "Amazing Correlation Between Google +1's and Higher Search Rankings" at Moz.com. Many readers misunderstood him to be saying that +1's cause higher search rankings. That false idea spread so rapidly that Google's search quality czar Matt Cutts felt impelled to post on Hacker News:
Just trying to decide the politest way to debunk the idea that more Google +1s lead to higher Google web rankings. Let’s start with correlation != causation.
A careful read of Shepard's post, though, makes it clear that he was not at all claiming that +1's directly cause higher search rankings. Rather he was trying to come up with a reasonable explanation for why Moz's extensive search ranking factors study had come up with such a high correlation between sites that rank well in Google Search and the number of +1's those sites have.
Shepard, working in part off my March 2013 post "Google+ SEO: How To" posited that the explanation may be the fact that Google+ profiles have Google PageRank authority ratings, and that embedded links in posts from those profiles pass some of that authority to the web pages to which they link. Since at least some of the +1's on a web page will result in share posts of the page to Google+, it is possible that those link backs are driving ranking power.
That's a plausible theory, but remains to be better tested and verified.
But that's not the only power of the +1 to increase your reach and influence. The +1 is most directly powerful in its effect on your Google network.
Plus One and Recommended Posts
Recently Google made a significant change to what happens when you plus a post on Google+. Previously, plussing a post had little apparent effect, other than to act as a social signal on the post itself. The number of +1's on a post could indicate to other viewers that the post might be worth reading and/or sharing. But there the +1 effect appeared to go no further.
But as of July 2013 plussing a post can now (potentially) create a "recommended post" in the streams of one's followers on Google+. A recommended post displays the person who plussed it above the post.
What posts become recommended post? Not everything a user plusses will become a recommended post. Google+ uses an algorithm to decide which plussed content will be shown to which users. You cannot do anything to cause a certain post to become a recommended post, other than plussing it which at least makes it possible.
Who can see your recommended posts? By default, any post you +1 can be shown potentially to anyone who follows you and is in your extended network. Your extended network is people whom you've circled, and people whom they've circled.
But wait....there's more. If a recommended post shows up in your stream and the original creator of the post is not someone you currently follow, Google+ automatically adds a nice "Add this person" call to action button that allows you to quickly add him or her to your circles.
This vastly increases the opportunities to increase the size of your Google+ network when people +1 your posts.
The Personalized Plus and Google Search
But the power of the plus extends beyond Google+ into Google Search.
When people use Google Search while logged in to their Google+ accounts (and increasing numbers of people do just that) they get search results boosted just for them based on the plussing activity of people in their Google network.
That result was placed higher than its "normal" rank in Google search for me because I was logged in to Google, and Brian Clark is in my Google network. (Someone in my network sharing a piece of content to Google+ can have the same effect.
The more extensive your Google+ network, the more influence you have on the search results of others.
Using the Power of the Personalized Plus
Knowing that +1's can have such a dramatic effect of promoting your content in both Google+ and Google search, what should you do to take advanage of the Plus plus?
Now go and practice the power of the personalized plus!