Despite a rapid product update pace and some pretty famous users, it sounds like Google+ is having a hard time keeping its users engaged. According to data from research firm comScore, Google+ visitors spent an average of three minutes per month on the site between September 2011 and January 2012. However, visitors to Facebook spent six to seven hours each month using the much larger social network. While that sounds like a remarkably wide gulf, some data we obtained from web measurement firm Compete corroborates comScore's findings — according to Compete, Google+ visitors went to the site less than three times a month and spent about three and a half minutes per visit (on average from July 2011 through January 2012). Facebook visitors, on the other hand, ended up visiting Facebook about 21 times each month, spending almost 20 minutes each time they visited. This works out to a little over 10 minutes spent on Google+ compared to about 7 hours spent on Facebook.

While it may be unfair comparing a service that has only been around for eight months with a giant of the industry like Facebook, it's obvious that Google+ users aren't terribly engaged with the service right now. However, it's far too early to make any real judgements on the networks long-term prospects or viability. One only needs to look to Twitter to see a social network that exploded in popularity several years after its initial launch. As of 2008, two years after Twitter's launch, 300,000 tweets were sent each day — but by 2009, that number exploded to 35 million per day. Google doesn't appear overly concerned yet, either: Google VP Bradley Horowitz said that Google+ was growing by "every metric we care about," and also noted that Google+ is meant to be more than a "destination site" and that it was hard for third-parties to accurately track the service. Overall, it feels a bit too soon to start writing an obituary for Google+.