Monthly Active User (MAU)

Monthly Active User (MAU) is a key performance indicator (KPI) often used by online games, mobile apps and social networking sites. MAU is calculated by counting the number of unique users for a 30-day period. Calculating MAU helps determine the value of a company and finds the number of users who participate with and return to the site on a monthly basis.

Broadly, monthly active users can be identified by an ID, email or username. For some companies, that requires a login and interaction, though what constitutes an interaction can differ between companies. Aside from a monthly basis, active users can be measured daily (daily active user) and weekly (weekly active user). Daily is often used by businesses that expect daily use, such as calendars, games and email. The weekly measurement is most often used by social communities or message boards, forums, analytics tools and productivity apps. The monthly active user metric is most used by business-to-business applications, such as email and bookkeeping/accounting applications.

Facebook considers a user to be a MAU if he has logged in and “used” Facebook within the month. “Used” is defined as interaction with the website: liking, sharing, commenting, messaging or clicking through on a link. If a user does not interact for a 30-day period, that user is considered inactive.

Twitter counts active users as those who follow at least 30 accounts and are followed back by at least one-third of those accounts. The MAUs are determined by counting active users who have signed in within the month.

MAUs at Google+ are those who have an account and used a Google service at least once in the month.

There has been much criticism of just how monthly active user figures are calculated, as well as whether the metric is relevant. For example, in Twitter's fourth quarter earnings call in 2015, it was stuck with the unenviable task of explaining why it had lost four million monthly active users during the previous quarter. The reason, it turns out, is because most of those four million users did not actually use Twitter. Rather, they had been counted when the iPhone Safari web browser performed an automatic Twitter data pull. After the operating system in use then updated, those users would no longer be counted. The question remains: how accurate are MAU numbers overall? At the time, Twitter co-founder Ev Williams said "it’s become so abstract to be meaningless,” as reported in an article in tech news journal Recode. 

Also in 2015, Facebook revised the way it defines MAU in response to skepticism of how accurate its figures were. It would no longer count what is known as "third-party pings" by people who were not actively using Facebook but had only shared content or activity via a website or application that was integrated via Facebook login.