Is Google+ a Ghost Town, and Does It Matter?

Google+ is a lonely place. At least according to a new study that paints the social networking site as a virtual tumbleweed town.

Using information culled from the public timelines of 40,000 randomly selected members, data analysis firm RJMetrics found that the Google+ population, which currently numbers 170 million, is largely disengaged, with user activity rapidly decaying—at least when it comes to public posts.

According to RJMetrics, 30 percent of first-time Google+ public posters don’t post again. Of those who make five public posts, only 15 percent post again. The average time lapse between posts is 12 days, and RJMetrics cites a cohort analysis showing that members tend to make fewer public posts with each successive month. And the response to public posts on Google+ is extremely weak. The average post receives fewer than one reply, fewer than one “+1″ (the equivalent to Facebook’s “Like”), and fewer than one re-share—basically most posts in the study did not garner any response.

Google (GOOG) contends that RJMetrics’s findings are inaccurate. They’re based on a small sampling of users and, more problematically, incorporate only data regarding public posts. Google+ was expressly designed to simplify sharing with select private groups, the company says, as opposed to sending public blasts à la Facebook. “More sharing occurs privately to circles and individuals than publicly on Google+,” reads a statement from Google. “The beauty of Google+ is that it allows you to share privately—you don’t have to publicly share your thoughts, photos or videos with the world.”

Google will not provide numbers on user engagement, but last July the company noted that people are two to three times more likely to share content with one of their circles than to make a public post.

Robert Moore of RJMetrics acknowledges that the study is skewed by the lack of private data, but points out that his findings echo a ComScore (SCOR) study released in February, which showed that Google+ users spent only about 3 minutes per month on the social networking site in January, compared with 7.5 hours on Facebook. “I think those data points reaffirm the underlying thesis, which is simply that engagement and retention are not strong characteristics of [Google+].” (A Google spokeswoman said the ComScore study, too, is inaccurate.)

Danny Sullivan, editor-in-chief of the industry blog Search Engine Land, says the RJMetrics study results are no surprise and likely present an accurate picture of Google+ user engagement. To put things in perspective, he points to a recent Lady Gaga post that received 570 “+1s” on Google+. The exact same post on Facebook got 133,539 “Likes.” “I don’t think they’re going to overtake Facebook, nor close the gap anytime soon—I think they’ll be a distant second for some time,” says Sullivan.

Still, Sullivan says Google+ provides Google with crucial user data to improve its main business: search. “Google+ allows Google to collect votes about what people like directly, which can help it in terms of its search ranking process,” he says. “Even if only 1 million or 2 million are active on the site, that might still be enough for them [Google] to get what they’re looking for.”