Lifetime value (LTV) refers to the total revenue expected to be generated by a player over the lifetime of playing a mobile game. LTV is not a measurable quantity but an expectation based on current information of how much revenue a group of users will generate. It is important to decide how much to spend on user acquisition based on estimated LTV. LTV is calculated by summing the past, present, and future revenues generated by a user over time based on factors like retention rates, conversion rates, and average revenue per paying user (ARPPU).