Changes in users' preference of services at different time scales

Because of possessing the huge superiority on selective services marketing [1], and that could bring tremendous research value, users' usage preference of network services is becoming an issue. But there was seldom research on changes in users' usage of network services at different time scales. In this paper, we investigated the changes in users' usage of network services at different time scales, and built an index system, which could be used to describe the relation of users' preference of network services at different time scales, included time scales, the extent of the changes in users' preference of network services, change point threshold for preference, change rate of users' preference of network services and etc. On this condition, in order to compare the similarities and differences of change rate for preference at different time scale and analyze the special points on change rate curve for preference, analysis and comparison of change rate for preference at different time scales and multiple change point threshold is necessary. The research results of this paper lay a foundation of research on selectivity marketing.