In one embodiment, a technique is provided for estimating and using an expected error of a position estimate of a WLAN-enabled mobile device produced by a WLAN positioning system. The WLAN-enabled mobile device receives signals transmitted by a plurality of WLAN access points in range of the WLAN-enabled device. The position of the WLAN-enabled device is estimated based on the received signals from the WLAN access points in range of the WLAN-enabled device. An expected error of the position estimate is based on at least one of a spatial spread associated with geographic positions of the WLAN access points, signal coverage areas of the WLAN access points, or a number of the WLAN access points. The expected error is used in providing one or more location-based services to a user of the WLAN-enabled mobile device.