ARPPUは「Average Revenue per Paying User(有料ユーザー1人あたりの平均収益)」の略称であり、一定期間に有料ユーザーがもたらす収益額を推定する指標です。
To calculate the ARPPU of an app, divide its total revenue by the number of paying users in the given time period.

ARPPU is vital for all apps that offer some kind of in-app purchases or subscriptions. It tells marketers and developers how much a paying user is worth to the business. Knowing this allows them to calculate how much they should spend to acquire a paying user.
Two metrics resemble ARPPU by name, but they are significantly different. These are ARPU and ARPDAU, so visit their glossary pages and learn more about them.