the late night hours to the same numbers every day.) Billing system information, such as revenue data, is relatively easy to obtain can yield some very interesting and useful insights. Reviewing Call-Detail Records The billing records present us with a distilled view of the customers' successful calling activities, but the call detail records themselves can provide us with a much more detailed insight into those customers. When we go to the call detail records (and the actual switching transaction logs), we are usually looking for one of two things. We want to know about the customers' less than successful attempts to use our service 2. We want to do an analysis of the physical locations from which people are using their phones eXcellence in Telecommunications The Telco Churn Handbook By looking at the actual switching records, we can figure out these particulars. Call detail and switching records tell us not only when a person has successfully completed a call, but also when the call has been dropped. This provides information about problems customers may be having with coverage or call quality. For wireless phones, the switching records of some systems identify which cells the customer is calling from and traveling through. Company Interchange Behavior The last kind of behavior that we want to consider is how the customer interacts with the company. A customer's track record as a credit and collections problem, as a constant complainer, as a monopolizer of customer service or sales resources, provides us with a valuable piece of additional information. With company interchange behavior, acquired from customer service and sales systems, we can begin to draw a truly accurate picture of the customer's behavior from all perspectives. DEMOGRAPHIC AND PSYCHOGRAPHIC SEGMENTATION The final type of segmentation that we will consider here is demographically and psychographically based. Much work has been done in marketing to explore the many facets of this form of segmentation and there is little that we can add here. In