Ann: Strategic Partnerships in Vietnam, page-14

a lot of people in China visits wechat numerous times to join talks and meet friends. People on wechat are organized into groups and each group has up to 100 people, they generally know each other very well. Each person may join several groups which cover different stages of his or her life. or different aspects of person's life, So, the messages, such as BFC sales, are spread in a group by any of the group members, I would say it happens randomly. What I saw is just one member turned up and tried to organise a group purchase of a family beef package (BFC brand). If any other member of this group become interested in this product, he or she may forward this message (with a picture) to other groups where he also is a member. That is the way the things get spread.