The metric everyone reports and nobody defines

Pick any company past fifty people and ask four teams for monthly active users. You will get four numbers and four confident explanations.

Where the versions come from

Product counts anyone who opened the app. Growth counts anyone who did something that matters. Finance counts anyone on a paid seat. Support counts anyone who could file a ticket. Each is defensible on its own and none of them agree.

The fix is boring

Write the definition down next to the number. Not in a wiki nobody opens, but attached to the metric itself, so that any answer using it shows the definition it used and the tables it read.

It is not a glamorous fix. It is the difference between a meeting about the business and a meeting about the numbers.