Abstract: The disclosed technology includes system and method for discovering key places for a mobile device based on historical location data associated with the mobile device. The key places are discovered by mapping the historical location data into predefined land areas in a geographical region, aggregating the historical location data into time interval sessions, selecting a first set of the predefined areas based on density of location data in each of the predefined land areas, and filtering the first set of the predefined areas to obtain the key places. The key places are used to estimate one or more travel routes routinely taken by a user of the mobile device, and to build an association database, where one or more billboards and/or points of interests near the travel routes are associated with the mobile device or its user. Information documents for delivering to the mobile device are selected based at least on data in the association database.

Abstract: Location data of a large number of mobile devices and map data are used to derive a large number of commute routes in a geographical area, which are used to build a relational database including associations between a plurality of road segments and a plurality of information documents. Each of the plurality of information documents corresponds to a billboard in the geographical area and includes information displayed by the billboard. A respective road segment in the relational database has one or more associations with one or more information documents, each of the one or more information documents being associated with the respective road segment by a corresponding probability value indicating a degree of likelihood of a traveler on the respective road segment being exposed to information displayed on a billboard corresponding to the each of the one or more information documents.