Google+, Google's (GOOG 0.56%) (GOOGL 0.69%) struggling social network, probably won't last much longer. In March, Google announced that it would unbundle the network's core Photos and Streams into stand-alone products.

This isn't the first time Google reduced the network's footprint. Last year, it dropped profile photos and Google+ circle counts from search results, claiming that they cluttered up search results. It then dumped Author Stats, a Google+ Authorship-based metric which users could access via Webmaster Tools.

My Google+ account. Source: Screenshot

Shortly afterward, Google+ founder and chief Vic Gundotra abruptly resigned. Bradley Horowitz, one of the site's main architects, subsequently took over the Photos and Streams products. If Google+ disappears, will Google ever have a chance at catching up to Facebook (META -1.12%)?

Google+ by the numbers
Google's official figures for Google+ are misleading, since many of its services automatically create accounts for the user.

In late 2013, Google claimed that the network had 540 million monthly active users (MAUs). However, those "active" users include people who use their Google+ linked accounts to access other Google services like YouTube or Gmail. According to The New York Times, half of those users did not visit the Google+ social network.

Those numbers meant that its user base was comparable to Twitter (TWTR), which reported 288 million MAUs at the end of 2014. Yet it was undeniably dwarfed by Facebook, which had 1.44 billion MAUs last quarter.

Google hasn't disclosed official Google+ figures since then. However, pseudonymous tech blogger Edward Morbius recently conducted an independent study by using an automated script to scan a sample of 21,000 Google+ accounts. According to those findings, just 9% of Google+'s 2.2 billion registered users, or 198 million people, have ever made a single public post. Of those, only 6% posted any content in the first 18 days of 2015, and half of those were linked YouTube comments. That leaves Google+ with less than 6 million "active users" who interact with its main site.

Why Google+ failed
If those bleak figures are accurate, Google+ will soon be headed for Google's social media graveyard, the final resting place of failed efforts like Orkut, Latitude, and Buzz.

Google+ failed to gain traction for three reasons. First, it launched far too late. When Google+ arrived in June 2011, Facebook already had around 800 million MAUs. Most people didn't need to cross-post photos or status updates to both. Second, it alienated many users by trying to straddle Facebook's private world and Twitter's public one with Circles and Sparks. This was done to address the privacy issues that occurred after Google tried to turn all Gmail contacts into social ones with Buzz, but it was far more confusing than "friending" or "following" a person.

Lastly, Google+ acts as a useful single sign-on (SSO) tool for all of Google's services, but there's no reason to visit the News Feed, which acts as a core for both Facebook and Twitter.

Why social networks matter
Google needs to "get" social soon, because Facebook is leveraging its massive user base to build a formidable ecosystem of its own. Facebook tethers third-party apps and sites to that ecosystem with SSOs. If users want to share content from those apps and sites with their family and friends, they're more likely to use the Facebook SSO than the Google one.

Since Facebook gathers user data which it can use to craft targeted ads, mobile apps linked to Facebook cut Google out of the picture. And as long as Facebook has the most popular social News Feed in the world, users will keep using it to log on to websites and apps.

Simply put, Google owns the world's most popular search bar, but Facebook demonstrates that connecting apps and sites back to its News Feed is becoming more effective for mining data than top-down searches.

What's Google's next social media play?
Google clearly hopes that it can take on Facebook's Instagram and Twitter by unbundling Photos and Stream into their own apps.

But considering how small Google+'s remaining user base likely is, it's unlikely that either service will succeed where Google+ failed. Google probably thinks that it can gain more users by bundling these apps into Android devices, but that practice has already come under scrutiny in Europe, where it now faces an antitrust probe. Google's other option is to buy an established social network. Twitter is a commonly cited takeover target, but paying at least $40 billion for an unprofitable company with slowing MAU growth could be a bad move.

It's unclear what Google should do after it finally pulls the plug on Google+, but it needs to make a move soon. Otherwise, more sites and apps will join Facebook's ecosystem and leave Google out in the cold.