However, controlling for variables such as the 4 P's is difficult in real-world situations. We're reluctant to experiment on people. Not everything that can be counted counts, and not everything that counts can be counted. They help people describe reasons for their behavior, but surveys can be plagued by problems in completion. They presume self-knowledge and a willingness to reveal it.
Marketers have a lot of data at their disposal.
They've got demographic data, purchase history data, and web tracking data. And that's just for starters. But many marketers could benefit from a map of customer attitudes. Using a perceptual map, marketers can create more compelling ads, refine media selection, and tailor content on web sites and in email messages. Since no interviewer is present, no interpersonal influences are possible.