Simply put, purchasing means that others help you buy what you need. Since the reason for looking for someone else to buy it must be that this product is not available in China or the price is very high, some people choose to let others buy it in order to save their time and energy. At present, the purchasing places of purchasing are generally Hong Kong, Japan, South Korea and Europe.
There are also various channels. Generally, e-commerce platform is selected, acquaintances, friends and classmates introduce each other, join a large number of potential customers' WeChat groups, and establish WeChat groups. I don't know when a group of "friends" will emerge in the circle of friends to do purchasing. Some of these people are international students, some live overseas, some travel abroad, and even a large part of them are just agents, and they don't know the information of the goods they buy.