Which stats and aggregates should we maintain?

[snarfed]

We'd like to start tracking aggregates and statistics for Bridgy Fed usage. We do a bit of that now, eg total users, broken down per network, current activity rate, etc. But we'd like more, notably historically over time, eg MAU/DAU, activity rate, etc. Sadly our data volume is already high enough - our current datastore is ~1T - that we don't keep all the raw data we'd need to calculate those kinds of things, either historically or going forward.

These kinds of stats would be useful for a number of things, notably conversations with potential funders.

(As a counterexample, Bridgy classic is small enough that I have kept all the historical raw data, mostly in cold storage, and I've regularly crunched and reported statistics for a long time: https://snarfed.org/2023-06-02_bridgy-stats-update-8 , https://snarfed.org/?s=bridgy%20stats . It's fun! Mostly 😁)

I don't expect to store all of BF's raw data long term, in any form, but I can estimate some stats historically, and more importantly I can start tracking them going forward. So, what do we want? Assume these are both totals and broken down by source and destination network:

• active users per day, month, ...?
• counts of activities/interactions across the bridge, broken down by type
• account migrations in, out, and across (eventually)
• custom usernames/handles
• remote "instances" seen, interacted with
• explicitly opted out users, instances?
• total domains seen/interacted with...?
• total interactions seen/handled, whether or not they get bridged?
• costs, both total and per user, per active user, per interaction
• ...?

cc @anujahooja