Sau 90 ngày, các mối nguy hiểm là thực tế không có khách hàng không kích hoạt lại. Một lần nữa, các quá trình kinh doanh cung cấp hướng dẫn. Các số điện thoại được dành riêng cho 90 ngày sau khi khách hàng để lại. Thông thường, khi khách hàng reacti vate, họ muốn giữ cùng một số điện thoại. | 414 Chapter 12 Days after Deactivation Figure Survival curve upper curve and hazards lower curve for reactivation of mobile telephone customers. After 90 days the hazards are practically zero customers do not reactivate. Once again the business processes provide guidance. Telephone numbers are reserved for 90 days after customers leave. Normally when customers reactivate they want to keep the same telephone number. After 90 days the number may have been reassigned and the customer would have to get a new telephone number. This discussion has glossed over the question of how new reactivated customers were associated with the expired accounts. In this case the analysis used the telephone numbers in conjunction with an account ID. This pretty much guaranteed that the match was accurate since reactivated customers retained their telephone numbers and billing information. This is very conservative but works for finding reactivations. It does not work for finding other types of winback such as customers who are willing to cycle through telephone numbers in order to get introductory discounts. Another approach is to try to identify individuals over time even when they are on different accounts. For businesses that collect Social Security numbers or driver s license numbers as a regular part of their business such identifying numbers can connect accounts together over time. Be aware that not everyone who is asked to supply this kind of identifying information does so accurately. Sometimes matching names addresses telephone numbers and or credit cards is sufficient for matching purposes. More often this task is outsourced to a company that assigns individual and household IDs which then provide the information needed to identify which new customers are really former customers who have been won back. Studying initial covariates adds even more information. In this case initial means whatever is known about the customer at the point of deactivation. This includes not .
