Tracking the number of users will be interesting - the barrier to account creation is effectively 0, so something to do with bio / profile creation or posting (active users) makes sense

Though I think the number of "lurkers" (non posting / replying accounts) on social media is usually ~90%

So can't discount accounts that don't meet a definition of "active". Maybe something about returning accounts, so how often requests are made to relays 🤷‍♂️