In fact, there are many kinds of offline transactions. Some transactions are conducted through Wangwang or QQ chats and then traded on Alibaba; some merchants in the same city will invite you to the store to talk. There are many other situations. As for security, it depends on how you consider it. Because if you leave a message for online transactions, the merchant will have some considerations about the price and quantity you offer, because it will affect their future transaction advantages, so many merchants will write offline transactions, but the key point is how the final payment is delivered, which is why it is recommended to use Alipay.