With literally hundreds of millions of consumers logging on to the internet and using social media every month, it’s no surprise that businesses have flocked to services like Facebook, Twitter and Pinterest.

Whether they’re looking to hawk their wares or listen to what customers are saying about them, there are numerous social media use cases that apply to just about every business under the sun.

But how many of the companies using social media are actually measuring what they’re getting from it?

According to a study conducted by Onepoll for software vendor EPiServer, the answer to that question is ‘not many’, at least in the UK. Of the more than 250 marketing decision makers surveyed about their organization’s use of social media, a disturbingly low (but perhaps not surprising) percentage (10%) indicated that they were effectively measuring ROI.

That doesn’t mean the other 90% don’t think they’re getting something out of social media. A quarter of those surveyed indicated that they’ve seen increased traffic, while a third are convinced that social media has increased customer loyalty and boosted customer engagement. A fifth even credited social media with increased sales.

The problem, of course, is that without an effective means of tracking ROI, it’s impossible to know just how much confidence companies should have in these figures.

Unfortunately, it appears the problem may only get worse. Over half of the decision makers surveyed indicated that their companies have increased the amount of time they’re spending managing their social investments in the past year. Nearly a third moved into a new social channel in 2011, and 17% expect to do the same this year. According to EPiServer, “Marketers now spend an average of an hour a day managing social media, with only 6% managing multiple channels centrally.”

Needless to say, the situation doesn’t look good. If companies can’t measure ROI from their social activities, but they’re spending more time and money managing their expanding social presences, social media has the potential to become a black hole for investment.

The good news is that it doesn’t have to be. Measuring social ROI may be difficult in some instances, but companies can help themselves keep an ROI within reach by making sure that they don’t overinvest in the channel before they know how to measure its impact.