RE: Hive Proposal Costs per Active User

Not really, we have over 2M accounts but ~8,000 actively posting. You could use posts, comments, votes, custom json, there are lots of things you can do, but it isn't an exact science. Top level posts is a good metric, but for example people like Smooth and Freedom don't post, Blocktrades and GTG rarely post but are very active.

Front ends can't really tell who is logged in as it is broadcasts.

In most ecosystems, those who participate are like 10% of the total users the rest are lurkers, but in our case I think that doesn't really hold true due to the rewards. There are certainly lurkers though, but it just can't be quantified. I think "votes" is less reliable as that is more likely going to be 2+ per real user and many voters are completely gone.

I think it is safe to say it is somewhere around 5,000-15,000, but no one really knows.