One of the biggest trends in the world…

http://www.scmp.com/news/china/society/article/2095576/rise-qr-code-and-how-it-has-forever-changed-chinas-social-habits

A QR code is a two-dimensional barcode with a random pattern of tiny black squares against a white background, capable of holding 300 times more data than a traditional one-dimensional code. According to internet consulting firm iResearch, payments made via mobile devices by Chinese consumers last year reached 38 trillion yuan (US$5.5 trillion, HK$43 trillion), more than half the nation’s GDP.
QR code scams rise in China, putting e-payment security in spotlight

Thanks to QR code’s rapidly increasing usage at off-line shops, the amount of mobile payments on the mainland is now 50 times greater than that of the US. Mobile payments in the US totalled US$112 billion in 2016, according to Forrester Research.
To consumer behaviour researcher Chen Yiwen, we are witnessing the dawn of “codeconomy”.
“China has started the transition to a cash-free economy faster than anyone could have imagined, largely because of the viral spread of two-dimensional barcode,” said Chen, a professor and researcher with the Institute of Psychology, Chinese Academy of Sciences in Beijing. “It creates a new economy based on scannable codes.”