According to a recently released report on social media usage in December, it hasn't taken long for Google Plus (GOOGL 0.55%) to gain traction. Google has alluded to the rapid growth of its relatively new social platform in the past, and it appears it wasn't just sales-speak.

Taking on Facebook (META -0.52%), with its 1 billion users and substantial head start, may have seemed like a stretch, much as Google's foray into mobile computing and the cloud did not long ago. But like with its Nexus phones and tablets and cloud computing solutions, Google's proving once again that it's not to be trifled with.

The results are in
It was early October when word began to spread about the popularity of Google Plus. Not only was the service growing by leaps and bounds with users -- Google put the number at 400 million, 100 million of which were "active" -- advertisers seemed to love it. About 55% of online advertisers named Google Plus a top five site for marketing, behind Facebook and Twitter. Not bad for the new guy on the block.

As it turns out, the momentum Google Plus was enjoying in the fall of last year hasn't waned one bit. According to a recent report by globalwebindex, Google Plus is now the second most active social media site on the Internet, as of Dec. 2012. A whopping 343 million Google Plus users are considered active, and that's in addition to the third most active social site, Google's own YouTube. Twitter, formerly No. 2 on the list, has dropped to fourth behind Facebook and Google's offerings.

What it means for Google
The growth of Google Plus has been nothing short of staggering, and the opportunities going forward are almost limitless. Whether you're a fan of Google or not, there's no denying it knows how to transition user activity to revenue; the recent Q4 financial results are a testament to that. The growth of Google Plus, and the opportunity to link multiple services through it, is what makes Google, well, Google.

As Facebook is learning, a ton of user activity doesn't mean much until it translates into revenues. Google certainly gets it, and, along with its diversified revenue streams, is a unique investment opportunity as a result. Interested in mobile computing? Sure, Apple's stock price has been beaten down lately, making it a pretty good value, and you can be certain it won't be long before the next iPhone launch.

Or maybe you're of the mind that cloud computing is where the investment opportunity is at. IBM's (IBM 1.05%) recent quarter is a great example of successfully transitioning into new, burgeoning markets. IBM's stellar quarter was due largely to its focus on cloud computing and services, rather than continue down the same, worn-out hardware path. Then there's Facebook. Even after a nice run to more than $30 a share, it remains an attractive alternative to invest in social media.

But here's the thing: Google owns the leading OS in the world, by far. With its purchase of Motorola Mobility, you can be certain its own smartphone, rather than the Nexus, which was developed in partnership with LG, is coming to an online store near you soon. Google is a legitimate alternative to Apple for a mobile computing play.

Google Plus is already a favorite among business users, and Google apps, analytics, and similar solutions make it a legitimate alternative to invest in cloud computing, much like IBM. Social networking, be it personal or business-related, is more than addressed with the explosion of Google Plus. You can see where this is heading, can't you?

There are very few investment opportunities like Google, certainly few that offer the level of market diversification and its history of stellar revenue growth. Whether Google Plus catches Facebook or not, you can be sure Google will be a force in social media, just as it is in every market it goes after.