Wired News: RFID: To Tag or Not to Tag: "Why is it becoming so popular?
Low-frequency RFID has been around for about 30 years, but it hasn't been practical for widespread use because manufacturing the chips and readers has been expensive.
Also, a lack of standards that would allow any RFID reader to scan any chip kept the technology from being widely adopted, but proposed standards could help change that. Some RFID tags now cost less than 50 cents.
Manufacturers like RFID because the technology is more convenient and durable than bar codes, which can be difficult to read if not passed directly in front of a scanner or if the bar code has faded or is torn on the product package.
An RFID tag can also hold more useful information than a bar code, such as the expiration date of a perishable product like milk."