This article presents an overview of chipless RF identification (CRFID) sensors and their applications in product tracking and identification. Current CRFID limitations include small read range, low data storage capacity and sensitivity, tag collisions and signal interference. New research directions are proposed for advanced signal processing techniques, robust anticollision protocols and strategies, new materials, consideration for tag density and memory constraints to overcome these limitations. Chipless RFID sensor networks have the potential to enable new efficient and productive industrial applications for Internet of Things (IOT) systems and smart infrastructures.