After receiving an indication that the user has requested a particular set of option data objects (such as the option data objects in a particular subcategory with option data object locations within a particular zip code) the radius r corresponding to the zip code the user is currently in and the subcategory of option data objects requested by the user is retrieved from a database. After retrieving the appropriate radius, the distance dist1 is computed as the distance between a particular option data object location and the particular location of the user. In some example implementations, the location of the user is determined based on information obtained from viewer device 410, which may be capable of interacting with a GPS system, a cellular communication system, and/or other location-determining systems to ascertain the location of the viewer device 410.