Sensor based technologies, since their integration into mobile phones, have started playing an important role in mobile based transactions. The note provides examples of sensor based communications in daily life. It provides a detailed explanation of the two most commonly used technologies - Near Field Communication (NFC) and Bluetooth Low Energy (BLE). Further, it looks at the applications of sensor communications in payments, promotions, couponing, tracking and positioning, personalization, customer engagements, and location based marketing.