Research scientists have a saying—“if you can’t measure it, you can’t count it.” No assumptions, guesswork or spidey sense—either you have the data to back your claim, or you don’t make it.

Should the same principle apply to your marketing efforts?

Yes, mostly, but with some caveats.

Marketing ROI draws its conclusions using measures that are quantitative—how many, how much—as well as qualitative—what did people feel, experience. And thank goodness, studies in ROI back up these claims! They tell us that the easiest ROI to measure are the results of email and direct marketing because you can count up responses. The most difficult are the PR and print ads because you’re trying to measure overall impression, the level of awareness raised, even impact from other campaigns.

Clearly, measuring ROI is a tricky business. So what’s a marketer to do?

Establish clear expectations about what you can and can’t measure, then find a way to do it. There are many excellent tools available these days and some actually do gauge customer experience and feelings.  Talk with ROI experts. Find out what is possible.

Acknowledge that a one-size-fits-all approach doesn’t work. Email may be the most straight-forward way to prove ROI, but you need to reach your customers in different ways. Don’t just opt for the easy-to-measure route.

Finally, find out a way to build in qualitative measures. In other words, make customer comments part of the evaluation process. In the world of marketing, direct, ‘feeling based’ customer feedback IS equally valid and valuable as long as you find ways to capture, record and report them.

In a recent study conducted by Anderson Analytics, the inability to measure the ROI of social media campaigns topped the list of concerns. But it turned out that the reason wasn’t that ROI couldn’t be measured, but that the marketing experts didn’t know that they actually could measure the results. Read more here.