An RFID chip in the luggage makes more sense. It is much cheaper and can be scanned remotely. It could be registered to you much like the chips they implant in pets. The airline wands your bag at check in, records the number in their system and on your ticket. If the chip is part of the bag, they could not fall off and it could help with security ( a quick check before leaving the arrivals hall could help prevent bag theft). A chip reader could scan the luggage at multiple points (load/unload/transfer, etc). Much like the bar codes now, but orientation of the bag or tag would not matter and it couldn't fall off.