YSK: Small talk is a very important preface to a conversation, as you can use it to guage a person's personality, mood, and level of extraversion, making choosing a topic to talk about significantly easier.
from /r/YouShouldKnow
YSK：闲聊是谈话的一个非常重要的前奏，因为你可以通过闲聊来猜测一个人的性格、情绪和外向程度，使选择谈话的话题变得明显容易。