This situation is divided into two types, one is offline and the other is online. Offline promotion: It is common that there are various small gifts on the roadside with QR codes in front. This kind of gift can be obtained by scanning the code, but this QR code is not necessarily safe, and some are scams. After scanning, all the information in your mobile phone will be leaked immediately. It is not recommended to take risks for a small gift. Online promotion: A series of user behaviors, such as QR code promoted by Pinduoduo, need to be downloaded by scanning code and registered. In fact, it is some strategies made by merchants to promote their products. In essence, they are taking advantage of people's greed and doing all kinds of things they want to achieve. A gift doesn't have much money, so it is not recommended that we scan the code to get the gift.