1. A method comprising, by one or more computing devices: receiving, from a mobile-client system of a first user, geographic-location information associated with the mobile-client system; calculating, for each of a plurality of candidate place-entities corresponding to the geographic-location information, a confidence score based on both the geographic-location information and social-graph information associated with the first user, wherein the confidence score represents a probability that the mobile-client system is located at the candidate place-entity; and sending, to the mobile-client system, information associated with one or more of the candidate place-entities based on their respective confidence scores.
16. The method of claim 1 , wherein the information sent to the mobile-client system comprises an advertisement associated with one of the candidate place-entities based on its respective confidence score.