The QR and the QR reader was invented nearly 40 years ago, however, like many wonderful inventions, the QR has exploded because of a mass market reader, namely the Smartphone.
Two types of QR make a huge difference
Static QR has no URL, simply links and very often to a long and complex URL
Link example: llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch.co.uk
Dynamic QR has its own dedicated URL
The anomalies of distributing QR
When you think about it, the QR is scanned on just one device, the hand held smartphone.
So if you send QR to a smartphone, e.g. on WhatsApp the phone user cannot scan it, can they?
And the other serious problem is that WhatsApp do not allow images with embedded links, unlike email or websites.
The rules of sending a QR on WhatsApp
Never just post the QR and assume it will get scanned, it almost certainly will not!
Always post the QR image alongside some copy and a "CALL to Action"