I think it stands for, you made it up. You still haven't given any citation whatever for that number.
> You gave a figure that is collected directly from the 'servers' page that literally says "Monthly Active Users".
It also literally says right below that, "Data collected by crawling all accessible Mastodon servers on Apr 15, 2023."
Look at the data. It has daily counts. For example, here's the April 15 data that matches with what the page says:
{"period":"2023-04-15","server_count":"9509","user_count":"6641082","active_user_count":"1201004"}
I think it's actually the "Monthly" label there that seems somewhat misleading, unless perhaps it means they update the page once a month.
In any case, as another commenter mentioned, DAU and MAU tend to be relatively close. You don't go from 1.2M monthly users all the way down to 50K daily active users, that's nonsense. https://news.ycombinator.com/item?id=35600846
Do you think Twitter has 6 billion MAU?