1. A computing device, comprising: at least one microprocessor; and memory storing instructions configured to instruct the at least one microprocessor to: convert, by the computing device, coordinates of locations of a first mobile device at a first plurality of time instances into first identifiers of geographical regions having predefined boundaries; determine, by the computing device, visitations of the first mobile device to a geographical region as a function of time based on converting of the coordinates of the locations of the first mobile device into the first identifiers of geographical regions; convert, by the computing device, coordinates of locations of a second mobile device at a second plurality of time instances into second identifiers of geographical regions; determine, by the computing device, visitations of the second mobile device to the geographical region as a function of time based on converting of the coordinates of the locations of the second mobile device into the second identifiers of geographical regions; determine, by the computing device, a difference in visitations to the geographical region, based on: the visitations of the first mobile device to the geographical region as a function of time, and the visitations of the second mobile device to the geographical region as a function of time.