Monthly active users (MAU) and ARPU
MAU counts users active in a month; ARPU is revenue divided by average users over a period, a measure of revenue per user.
MAU is the number of unique users who complete a qualifying action in a month. Each company defines its own qualifying action, so MAU is not comparable across companies. ARPU, or average revenue per user, is usually revenue divided by average users in the same period.
Traders care because user growth measures reach and ARPU measures monetization. A platform can raise revenue by adding users, by increasing ARPU, or both. Check whether a change in MAU reflects a definition change, and whether ARPU is driven by a price change, a mix shift or a change in regions.
Worked example (illustrative numbers, not real data): quarterly revenue is 900 million dollars and average MAU is 150 million, so ARPU is 6 dollars per user per quarter. If MAU rises to 165 million and ARPU stays at 6 dollars, quarterly revenue becomes 990 million.