A method of estimating a geographic location of a WLAN-enabled user-device in a WLAN-based positioning system having a plurality of WLAN-enabled access points (602, 603, 604), the method comprising: the WLAN-enabled user-device receiving signals transmitted by WLAN-enabled access points in range of the WLAN-enabled user-device so that observed WLAN-enabled access points identify themselves; accessing a master database that associates WLAN-enabled access points with corresponding geographic locations for the WLAN-enabled access points as determined by an audit of a geographic area and obtaining geographic location information for any identified WLAN-enabled access point in range of the WLAN-enabled user-device; accessing a supplemental database to obtain inferred geographic location information corresponding to any identified WLAN-enabled access point in range of the WLAN-enabled user-device, the supplemental database having a set of WLAN-enabled access points and corresponding inferred geographic locations, the inferred geographic locations being inferred based on a package including input by a user of the WLAN-based positioning system, wherein the package includes a user ID, information about WLAN-enabled access points in range of the WLAN-enabled user-device and user-tuned location information; and estimating a geographic location of the WLAN-enabled user-device based on the geographic location information obtained from the master database and the inferred geographic location information obtained from the supplemental database, wherein the inferred geographic location of any WLAN-enabled access point is an estimated current geographic location of said WLAN-enabled access point determined from the package created in response to a location tuning request from the user. the WLAN-enabled user-device receiving signals transmitted by WLAN-enabled access points in range of the WLAN-enabled user-device so that observed WLAN-enabled access points identify themselves; accessing a master database that associates WLAN-enabled access points with corresponding geographic locations for the WLAN-enabled access points as determined by an audit of a geographic area and obtaining geographic location information for any identified WLAN-enabled access point in range of the WLAN-enabled user-device; accessing a supplemental database to obtain inferred geographic location information corresponding to any identified WLAN-enabled access point in range of the WLAN-enabled user-device, the supplemental database having a set of WLAN-enabled access points and corresponding inferred geographic locations, the inferred geographic locations being inferred based on a package including input by a user of the WLAN-based positioning system, wherein the package includes a user ID, information about WLAN-enabled access points in range of the WLAN-enabled user-device and user-tuned location information; and estimating a geographic location of the WLAN-enabled user-device based on the geographic location information obtained from the master database and the inferred geographic location information obtained from the supplemental database, wherein the inferred geographic location of any WLAN-enabled access point is an estimated current geographic location of said WLAN-enabled access point determined from the package created in response to a location tuning request from the user.