Geo-fencing is a location based service that allows sending of messages to users who enter/exit a specified geographical area, known as a geo-fence. Today, it has become one of the popular location based mobile marketing strategies. However, the process of geo-fencing is presently manual, i.e. a retailer must specify the location and the radius of area around it to setup the geo-fences. Moreover, this process does not consider the user’s preference towards the targeted product/service and thus, can compromise his/her experience of the app that sends these communications. We attempt to solve this problem by presenting a novel end-to-end system for automated creation of affinity based smart geo-fences. Affinity towards a product/service refers to the user’s interest in a product/service. Our unique formulation to estimate affinity, using historical app usage data, is sensitive to a user’s location as well and thus, the affinity is termed as location sensitive product affinity (LSPA). The geofence logic tries to capture contiguous groups of locations where the affinity high. Experiments on real world e-commerce dataset reveals that geo-fences designed by our approach performs significantly better at accurately targeting the users who are interested in a product. We thus show that, using historical app usage data, geo-fences can be created in an automated manner and help enterprises target interested users with better accuracy as compared to the present industry practices.