1. A method of estimating demographic information associated with a user of a mobile device while preserving privacy of the user based at least in part on a location estimate of the mobile device of the user, the method comprising: (a) receiving an estimated geographical location of the mobile device of the user; (b) receiving a time at which the mobile device was at the estimated geographical location; (c) providing a set of substitute identifiers for a corresponding set of at least one geographical area; (d) assigning one of the set of substitute identifiers for a geographical area corresponding to the estimated geographical location of the mobile device; (e) assigning a substitute identifier for the time at which the mobile device was at the estimated geographical location; (f) retrieving, from a non-transitory computer readable medium, demographic information corresponding to the substitute identifier for the geographical area and the substitute identifier for the time; and (g) forming a device demographic profile based on the demographic information corresponding to the substitute identifier for the geographical area and the substitute identifier for the time, wherein the demographic profile stores statistics of the mobile device that serve as demographic information for the user of the mobile device.