Ask HN: What Does a Social Media Analytic Want and Do?

I want to build a social media analytics toolkit for Bluesky (and possibly expand it to every social thing I use) just because I can. I have a crapload of time, and I want to put it into building a tool for a domain I don't quite understand with people that do understand. It all comes down to a question, which data does a user need and in which wrap?

So, I'm asking it - what do you measure, plot, and derive as a social media analytic? What would you if you were one?