INTRODUCTION
In recent years, data-based marketing has swept through the business world. In its wake, measurable performance and accountability have become the keys to marketing success. However, few managers appreciate the range of metrics by which they can evaluate marketing strategies and dynamics. Fewer still understand the pros, cons, and nuances of each.
In this environment, we have come to recognize that marketers, general managers, and business students need a comprehensive, practical reference on the metrics used to judge marketing programs and quantify their results. In this book, we seek to provide that reference. We wish our readers great success with it.
1.1 What Is a Metric?
A metric is a measuring system that quantifies a trend, dynamic, or characteristic.1 In virtually all disciplines, practitioners use metrics to explain phenomena, diagnose causes, share findings, and project the results of future events. Throughout the worlds of science, business, and government, metrics encourage rigor and objectivity. They make it possible to compare observations across regions and time periods. They facilitate understanding and collaboration.
1.2 Why Do You Need Metrics?
" When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind: it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science."—William Thomson, Lord Kelvin, Popular Lectures and Addresses (1891-94)2
Lord Kelvin, a British physicist and the manager of the laying of the first successful transatlantic cable, was one of history's great advocates for quantitative investigation. In his day, however, mathematical rigor had not yet spread widely beyond the worlds of science, engineering, and finance. Much has changed since then.
Today, numerical fluency is a crucial skill for