Electronic Article Sureveillance EAS
Some RF tags contain no information. They are not RFID because they are detected as simply there or not there - call it 'one bit' of information. These are usually employed as anti-theft devices in shops and libraries, and are called Electronic Article Surveillance (EAS). New forms of RFID perform EAS functions as well, obviating the need for a separate device, and adding more value to the tag. All the main three EAS technologies have been developed into RFID versions, albeit at higher costs. An EAS tag costs about 2 to 6 cents because it does not need a silicon chip. The RFID developments of these are also called "chipless".
6 billion EAS tags were sold in 2003. The main suppliers are Checkpoint Meto and Tyco Sensormatic.