i think its quite common that people use QR code readers... im always using mine. The labels and tags can also hold as much info as needed and you can track when its scanned.
Uses: luggage, pets, alzheimers patients, pets, people with allegies, kids (great for kids when your out in a large populated space - we have tshirts with qr codes), car dealerships, keychains, laptop, cell phones and the list goes on
