The Dutch firm SEO Effect has released a white paper on the impact of +1's on SERPs, reporting that its website saw 20 percent more traffic after it garnered +1's. While the study's methods leave something to be desired, the highly desirable results are worth investigating.

The company asked readers to +1 its website on SERPs in exchange for a service valued at $9, and 73 consumers responded. Once users who were logged into their Google accounts gave experiment pages a +1, they were then asked to retweet these pages to let the company know they had participated.

So what share of increased visibility comes from +1 and what share might be a result of the retweets? SEO Effect is the first to state that its methodology is somewhat unreliable. “It is impossible to measure the effect of the +1 votes on rankings in isolation,” it says. The company also acknowledges that 73 participants don't offer conclusive evidence on the value of Google's +1 service.

All that said, the company reports that it saw a 20 percent increase in rankings and corresponding gains in clicks and visits for various keywords following the +1 experiment. SEO Effect hypothesizes that the +1 data can boost rankings (and Brafton has reported that Google's Matt Cutts has suggested +1 will become a ranking signal).

The company also points to some issues it found with the +1 button that other marketers will want to watch. For instance, SEO Effect learned the hard way (after changing the name of a blog post to be more SEO friendly) that +1 data is lost on pages with 301 redirects. This seems like a wise move on Google's part as transferring +1's could be a way to abuse social currency.

SEO Effect's white paper also points to the current limits of having +1 data visible on SERPs. Google users must be logged in to their accounts to see +1 data, and even then, the company did not always see anonymous +1 data in search results for pages within the experiment.

This study monitoring +1 effects may be lacking conclusive evidence, but the white paper joins the growing buzz for +1 in the internet marketing community. Perhaps what marketers should be monitoring is whether consumers seem to adopt the idea of +1. It is positioned to be a service comparable to Facebook Likes on Bing – and Brafton has reported that many searchers are expressing their interest in Bing's insight on social relevancy. Brands might also want to focus on their content marketing approaches and produce web pages that are social-friendly, encouraging shares via +1's, tweets, Likes and any other social platform consumers choose.