y into several categories. Whether or not this lack of mutual exclusivity is a problem depends on what the segmentation will be used for. Exclusivity - Only An Issue in Certain Situations If the segmentation is a targeting segmentation - used to help us identify a group of people to pursue for a particular activity - then this mutual exclusivity is no problem. Likewise, if the segmenta- tion is a descriptive segmentation- helping us to understand the Figure 11-3: Multi-membership Segmentation Chapter 11 characteristics of individuals - then mutual exclusivity is no re- quirement. If, however, the segmentation is used for measuring purposes (to measure the effectiveness of a channel, campaign, or activity) or for structural purposes (to define how the general population will be covered) then mutual exclusivity is a must. Problems with All-Inclusiveness Next, let's consider situations where all-inclusiveness is a problem. Assume that we have created a segmentation scheme that includes age, sex, and income as the defining characteristics and that we have identified young females (ages 15-25) with incomes of between $40,000 and $65,000 per year as one primary segment of high value and another segment of males (ages 45-60) with incomes of between $65,000 and $85,000 as the other primary segment. Figure 11-4: Inclusiveness The organization will then create strategies and programs that address these groups. However, no matter how good this segmentation scheme may be, we inadvertently have created a problem at the same time. What about all of the other segments in our population? A great many people could be very good customers but are not included in these two primary segments. Since our segmentation scheme is not all-inclusive, we have left a large part of the population out. eXcellence in Telecommunications The Telco Churn Handbook This kind of segmentation scheme can provide all sorts of problems for the organization if employees try to use it too literally. For example, what does the sales or customer service organi