Location-based marketing uses technologies like Bluetooth, GPS, RFID, and WiFi to determine a customer's location and send targeted ads and offers to their smartphone. This allows marketers to reach consumers in the right place and time with relevant messages. Some technologies used are Bluetooth to exchange data over short distances, RFID tags to track object movement, and iBeacon to send push notifications to devices in close proximity. While this can increase sales and ROI through real-time special offers, there are also privacy concerns like spam and potential for misleading ads.