What is the essence of lost user operations? Its essence is the loss category email list early warning based on user big data analysis. Churn early warning requires operations to be able to accurately predict which users are facing churn based on user churn characteristics? Is it a high-value user of the platform or a general-value user? We discuss how to build a user category email list churn early warning system from three aspects. What is the essence of lost user operations? This is category email list one of the most challenging subjects in user operations. I believe that many companies are very concerned about this topic. Maybe the big boss of the operation will stare at the user data panel and shout loudly: Why is the user churn rate so high? Are you doing recall of lost users? At this time, many people category email list answered that the essence of the operation of lost users is not to recall lost users! As a result, operators will set up a system category email list of recalling lost users. A common operation scenario under the guidance of this system is to define users who have not logged in or purchased for a period of time as lost users; plan recall activities and use push or text messages to reach users. The user operations of many enterprises are repeating this category email list kind of work, but they will find that the recall probability of lost users is very low. On the one hand,