An online system estimates a lift in foot traffic at a store in response to an advertisement campaign at the online system. The online system identifies a physical location for the store and obtains location data for a base group of users and a lifted group of users, where the lifted group of users receives advertisements associated with the store and the base group of users does not. The online system computes a distance between the location of the store and the user's location to create a base distance array for the base group and a lifted distance array for the lifted group. The online system then determines an aggregate value that represents a measure of a number of users visiting the store for each of the base distance array and the lifted distance array, and estimates a lift in foot traffic by comparing the two aggregate values.