A method and system for verifying the continued presence of the same player at a device such as a gaming machine without identifying the identity of the player is provided. The system comprises a device for continuously obtaining verification data samples, wherein each verification data sample relates to one or more physical features of a first player. A subsequently obtained verification data sample is analyzed to determine whether it is substantially similar to a previously obtained verification data sample. If the subsequent verification data sample is substantially similar to the previously obtained verification data sample, then the system determines that the first player continues to be the same player present at the gaming machine.