Consumers are all around you, and they’re shopping for, buying, and using products. Observing consumers, and finding something new and of value from doing so, isn’t hard. And even business-to-business marketers (who sell to other businesses rather than end-consumers) can find plenty of evidence about their customers at a glance. For instance, the number and direction of a company’s trucks on various roads can tell you where its business is heaviest and lightest.

Despite all the opportunities to observe, most marketers are guilty of Sherlock Holmes’s accusation: “You have not observed, and yet you have seen.” Observation is the most underrated of all research methods. For example, years ago, managers from the Boston Aquarium wanted to find out which attractions were most popular. They hired a researcher to develop a survey, but the researcher told them not to bother. Instead, he suggested they examine the floors for wear and for tracks on wet days. The evidence pointed clearly to certain attractions as the most popular ones: The floors in front of those attractions had the most wear, and damp paths led to the attractions that visitors preferred to go to first.

Find a way to observe one of your customers as he uses one of your products (note the emphasis on observe; don’t just watch). Be nosey. Bring along a pad and pencil and take care to notice the little things. What does he do, in what order, and how long does he spend doing it? What, if anything, does he say? Does he look happy? Frustrated? Disinterested? Does anything go wrong? Does anything go right – is he surprised with how well the product performs? Take detailed notes and then think about them. I guarantee that by doing so you end up gaining at least one insight into how to improve your product.

You can gain insight into what your consumers care about, how they feel, and what they like by observing them in action. Being a marketing voyeur provides you a most useful and interesting way to do research – at no charge.

And if you’re in a retail business, be (or ask someone else to be) a secret shopper by going in and acting like an ordinary customer to see how you’re treated and get a feel for what you do and don’t like.