To exactly count the residence time of a client device in a WEB page.

When the content data of the WEB page is transmitted from a WEB server device 20 to the client device 10 for the first time, the initial access time information is added to content data of the WEB page based on a request from the client device 10 and when the client device 10 accesses the WEB server device 20 again, the initial access time information is transmitted to the WEB server device 20. On the other hand, the client device 10 accesses other WEB server device different from the WEB server device 20 or when the client device 10 terminates a browse function of the WEB page, the initial access time information is transmitted to the residence time counting server device 30. The residence time counting server device 30 counts residence time on in the WEB page based on the current time and the initial access time information.