o smaller, more manageable sub-populations. Segmentation to Create a Distilled Understanding of Customer Wants, Needs, and Characteristics Because telecommunications companies have many thousands of customers to deal with, there is no way to learn and attend to all their individual needs and wants. We need to find out what large numbers of people are interested in. That way, we can make the most people happy with the least effort. Segmentation is the discipline that allows us to do this kind of analysis and prioritization. Segmentation to Set Measurable Goals Finally, segmentation provides us with the ability to set goals and measure how well we meet them. For example, say that we wish to prevent the churn of 10,000 customers over the next six months. That is a good high-level metric to address. To determine how we will accomplish this objective it will be very helpful to understand how many of those retained customers have what kinds of background, history and revenue base. Segmentation allows us to make our goals trackable and executable in a very real, tactical sense. SEGMENTATION MEMBERSHIP RULES Another interesting issue in segmentation is that of exclusivity and inclusivity. Basically, for every segmentation scheme we create we need to consider how we will handle uncertain customer segment memberships. The purist school of thought teaches that segmentation schemes should be mutually exclusive, (that is, a customer placed into one segment cannot also be placed into another) and all-inclusive (that is, all customers must fit into one of the segments we have created). However, this presents some challenges during actual segmenta- tion. Chapter 11 Mutually Exclusive and All-Inclusive: An Example In some situations, the use of exclusivity and inclusivity rules makes perfect sense. For example, when dealing with geographic segmentation, exclusivity and inclusivity is automatic. People only live in one place at a time and SO our segmentation naturally enforces mutual exclusivity and complete inclusivity with no re