Keyword terms are most common on advertisements in trains, where it wouldn't be polite to use your phone to scan a QR code (and difficult to do to because of th

Keyword terms are most common on advertisements in trains, where it wouldn't be polite to use your phone to scan a QR code (and difficult to do to because of the position of the ads). QR Codes are used most often on things you are given personally, such as flyers or coupons.