Companies are using location-based marketing in a number of ways to connect with customers. Some tend to stick with only one tool to keep things simple. Others use all of the tools to stay connected with their customers on a variety of fronts.Location-based services (LBS): mobile apps such as foursquare and SCVNGER that provide information or entertainment to users based on their location. Near-field communications (NFC): technology that allows two devices that are in close proximity -- between two and 20 centimeters -- to exchange information. Bluetooth marketing: like NFC, this allows data transfer over short distances. If you've used a wireless phone headset, it probably was Bluetooth. Location-based advertising (LBA): uses tools such as GPS and geo-fencing to locate potential prospects and send them messages.