A system and method provides efficient and highly reliable customer tracking. A Personal Digital Key (PDK) is associated with and carried by a user. The PDK wirelessly communicates with a receiver/decoder circuit (RDC) that can be coupled to a variety of electronic devices. The RDC authenticates the PDK based on received data and stores information to track customers and provide improved service. A PDK can be assigned to one more groups of PDKs based on the received data. Specific functions can then be executed based on the group assignments. In a casino environment, the system enables functions such as group gaming, back betting, event tracking, and notification services.