What is a Monthly Active User?
A monthly active user (MAU) is a user who opened an app at least once in a specific month.
The total number of monthly active users shows you how many people use your app on a monthly basis.
Significant positive changes in the number of MAUs might be caused by successful user acquisition or retention marketing measures. Declines can be the result of missing retention marketing measures (like a proper onboarding process), a lack of content that keeps the app interesting, or other design errors that make the app uninteresting for long-term users. But it is also possible, that seasonal reasons cause a falling number of MAUs.