4. The method of claim 1 , wherein the geographic-location information comprises signal-information associated with one or more signals received by the mobile-client system, the signals comprising a Global Positioning System (GPS) signal, a Wi-Fi signal, a BLUETOOTH signal, a cellular signal, or a near field communication (NFC) signal.
5. The method of claim 4 , wherein the signal-information comprises a signal strength of one of the signals or an identifier of a device that sent one of the signals.