PURPOSE: A CRMS(customer relationship management system) is provided to offer customer information to a shop terminal by detecting a frequency of an RF(Radio Frequency) mode through a sensor if the customer holding a customer card including an RF transmitter approaches within a constant distance and by searching matched data from a customer management server. CONSTITUTION: A signal generator(220) generates a constant frequency and transmits an RF signal through a transmitter(230). A detecting sensor(300) receives the RF signal from the customer card(200) within a detection area and transmits an identification signal to the customer management server(100). The customer management server(100) comprises an input/output part(110), a CPU(120) and a customer information database(130). An input module(121) of the CPU(120) receives the identification signal transmitted from the detecting sensor(300) through the input/output part. A searching module(120) searches and extracts the customer database matching with the identification signal. The customer database is transmitted to the shop terminal(400) through the input/output part(110) of the customer management server(100).
