US Patent 9002375 Presence detection based on crowd surfing signal strength

A method includes receiving wireless signals from consumer devices that are in communicable range of the merchant device. The wireless signals each include a unique identifier associated with one of the consumer devices. The method further comprises generating signal strength data that includes one signal strength value associated with the unique identifier of each of the wireless signals, storing the signal strength data in a data storage device, analyzing the signal strength data to determine how many of the consumer devices achieved various signal strength levels, determining a threshold signal strength value based on the analysis, determining a consumer device is present within a physical area when a subsequent wireless signal from a subsequent consumer device is greater than the threshold signal strength value.