Daily Active Users

Daily Active Users, abbreviated DAU, is a counting metric from the digital economy. It indicates how many different people used an app or a website on a given day. Each person is counted only once, even if they open the app ten times that day. The difference from the total number of registrations is crucial: a service may have 500 million registered accounts, but only 20 million people who actually opened it today. Only those 20 million count as DAU. The English term has also become established in German, appearing almost always untranslated in quarterly reports and stock market news.

Why investors stare at the DAU figure

Registered accounts are a flattering number. It can only grow, since nobody deletes their old account. Dead accounts, abandoned profiles and duplicate sign-ups remain in there forever. DAU, by contrast, can fall. That is precisely why it is considered the more honest metric.

For companies that earn their money through advertising, revenue is almost directly tied to this figure. Anyone who doesn't open the app today sees no ads today. Large social networks therefore calculate internally with a revenue figure per active user per day. If DAU drops by a few percentage points, expected annual revenue drops by billions. Stock prices often react more strongly to such announcements than to reported profits.

For AI products too, this metric has become a benchmark. A chatbot that millions of people try out and never open again is economically worthless. It only becomes interesting once people build it into their daily work. With AI there is a special twist: every request costs the provider computing power. High DAU figures here therefore mean not only more revenue, but initially also higher costs.

What exactly counts as "active"

There is no official definition of "active." Each company decides for itself what gets counted. Some count every app opening. Others require a genuine action, such as sending a message or watching a video. When comparing two companies, one therefore has to look at the fine print of the quarterly reports.

Technically, the count runs via identifiers. For logged-in services this is the account ID, otherwise a device or browser identifier. This creates typical inaccuracies: someone using the same app on a phone and a laptop is easily counted twice. A shared family account, on the other hand, is counted as one person. Automated programs, so-called bots, have to be filtered out by the company.

DAU usually only becomes meaningful in relation to its monthly sibling, Monthly Active Users or MAU. Dividing DAU by MAU yields the stickiness of a service, known in industry jargon as stickiness. A value of 0.5 means: someone who uses the service during the month opens it on average every other day. Messengers often reach above 0.6 here, while travel or tax apps sit well below that. A low value is not automatically bad, it simply fits a different kind of product.

DAU in quarterly figures and headlines

The figure appears most often in the quarterly reports of publicly listed tech companies. Meta, Snap or Spotify report their current user numbers there along with the year-on-year change. Journalists pick out exactly this line. Headlines like "user numbers stagnate" almost always refer to DAU or MAU.

A common misconception is to equate the DAU figure with the number of people who like a service. It only measures presence, not satisfaction. A service can temporarily boost its numbers with intrusive notifications while annoying its users. Experts therefore also look additionally at time spent and churn rate.

The metric is also present outside the stock market. Anyone who publishes a small app or a school project online will find it in analytics tools such as app store statistics. There it appears with the same logic, just with three-digit rather than nine-digit values.