Back in the days when I was doing a lot of direct marketing, all of our campaigns were based on research, analysis, and testing. Try taking a course in marketing, advertising, or PR, each begins with a discussion about the importance of doing these tasks before launching a new program. But still, many companies and executives don't find the time or budget to do this work. Here is a video that shows the importance of research and testing, what the video calls "evidence based marketing."
Also of interest, is the way this video was created. This visual explanation ties back to an earlier post about how people learn and process information. It's simple but quite effective.