Methods and systems for creating demographic profiles of mobile communication network users. A demographic classification system analyzes network traffic, so as to estimate the specific combination of application classes installed on a given terminal, and usage patterns of the applications over time. This combination of application classes and their respective usage patterns are a highly personalized choice made by the user, and is therefore used by the system to deduce the user's demographic profile. The demographic classification system operates on monitored network traffic, as opposed to obtaining explicit and accurate information regarding the installed applications from the terminal. The system then deduces the demographic profile of the user from the list of estimated application classes.