This document discusses three emerging approaches to location-based marketing on smartphones: 1) GPS-based marketing which uses a phone's GPS to determine location and target ads, 2) geofencing which uses app-based virtual boundaries to trigger ads when a user enters or exits an area, and 3) zone and point-based marketing which delivers ads to specific shops or spots. It provides examples of each approach and tips for implementation, noting that while adoption is still challenging, location-based marketing offers opportunities to reach customers on mobile.