In the course of our ever-evolving research on Social Media trends (Do you not do this? You should.) we discovered a great whitepaper on the effects of the Google +1 button and how it affects impressions, traffic, and overall search rankings, when placed on a website. SEO Effect Tools did an experiment, with "over 70 readers of SEO Effect voting '+1' for three pages in the Google search results." From the results of the whitepaper, SEO Effect's opinion is that adding the Google +1 button to a website offers much more benefit than adding a Facebook Like button to a website. And it's incredibly easy to do.
The Google +1 Button
Google has included a few interesting perks for +1 users - for starters, when someone clicks on the +1 button, the social influence of the link increases, improving the link's chance of relevancy in search results. Not only that, but the click throughs increase because, as SEO Effect Tools writes, "social recommendations from a circle of friends are often even more convincing than expert reviews." Because the +1 vote from a user in a social circle offers annotations (unlike the Facebook "Like" button) the link "sticks out" in search results, leading to an increase in traffic.
Another welcome result of having the +1 button on a website is that when the button is clicked, Google bot is notified, and automatically re-crawls and indexes the page in question. If there were any doubt about adding the +1 button to your website, this result is an affirmation that the Google +1 button is useful.
SEO Effect's Experiment
First off, SEO Effect found that participation was restricted to users who were logged in to Google Services, and the results were based on the browser. The effect from the SEO Effect +1 experiment on the impressions and click through rates from search results to the site was short lived. However, it is a significant ranking signal in Google Search Results.
SEO Effect noticed that having +1 votes for content seemed to raise the content's traffic share. Though the page that was promoted via the +1 button did not receive more impressions, the average position for certain keywords rose by about 24%. The pages with those keywords received more clicks, and overall, the average search position of the page rose by about 20%. This could be due to the fact that even if you're not signed into a Google Account, the results may display the number of +1's a link has, giving that link validation of authority. Of course too fast, or too large increases in +1's activate a damping algorithm - Google's method of combating "fraudulent" +1 clicks.
Is it a Worthwhile SEO Tactic?
Aaron Wall of SEObook.com says,
"For most people I see it as a waste of time & an added jump to hoop through. User adoption has been abysmal, but you can count on Google tilting their relevancy algorithm (and announcing intention to it) to drive adoption, just like they did with the Google Checkout buttons on AdWords ads."
It's still a social signal, however, and since offpage SEO is incredibly difficult with the Panda update limiting many linking practice, social signals have gained a new importance. +1's, Facebook likes, and Tweets of your content hold a lot of weight in offpage SEO. Combined with good onpage SEO tactics, these social signals give your brand trust and authority in an increasingly populated world wide web. And since so many people use Google Accounts, social search has a lot more impact than it would seem at first.
The RoryMartin.com team recommends adding a +1 button to your site. The code isn't hard to implement and the offpage SEO benefits outweigh the relatively small task of adding code to your website.