Accurately speaking, Kaixin.com and Renren.com are not social acquaintances. About 1/3 of them are strangers and come through friends of friends. The criterion is whether it is allowed to send it directly to Friend Request through search. Acquaintance socialization is equivalent to QQ plus must be verified by friends.

5460 and alumni record are acquaintances socializing, but they have been tepid, because once they leave school, the frequency of relying on SNS is limited, or more of their instant communication is carried out through QQ group.

QQ group is a blow to acquaintances. Many acquaintances in China want to communicate with each other, so they can often set up a QQ group and hang it all day.