Messenger Pin is a feature resides in Facebook Messenger that allows users to mark important conversations for a certain period of time, and keep them highly accessible with just two taps away.
As a reoccurring pattern while using Facebook Messenger, referring to specific messages in the chat history is common for many users, and those messages themselves are in fact important information.
For example, users often plan and arrange trips on Messenger, and they will send each other dates, addresses, or even subway maps.
However, as they keep the conversation going, those planning details get pushed up in the chat, so finding them becomes annoying hassles, tedious scrolling and exhaustive searching.