A virtual reality device is configured to generate realistic images, sounds and other sensations that replicate a real or imagined environment for a user. As a first user interacts with the device, first user interaction data representing interactions between the first user and the device during a first user visit are recorded. A first unique visitor fingerprint is generated based on the first user interaction data. As a second user interacts with the device, second user interaction data representing interactions between the second user and the device during a second user visit that is different from the first user visit are recorded. A second unique visitor fingerprint is generated based on the second user interaction data. The first and second unique visitor fingerprints are compared to determine whether the second user is the same as the first user. Based on the determination, one or more functions can be performed.