20, 000 pair of eyes is pretty good! That's quite the audience. I'm with you that most people will discover it like you did, reading articles on other social media and will have nothing to do with the earning potential, it will just be a bonus. I do the same thing, I just share the articles with my peeps and say noting about hive and let the work do the talking. I joined in a similar way, read a few articles and thought this place was wholesome and I decided to join, I never had any intentions on actually blogging myself or knew anything about cryptos, I just liked the content and the idea that anybody could create rather than just a select few and now here I am making my way and learning how to build my own self-sustained path for the future and getting my photography out there with no social media experience or audience before steemit...As you said "Which is pretty much a textbook example of how "normal people" become part of web communities."
I can't say I have the same audience you do yet hehe. I do share my recipes on my personal facebook and drop links to random related pages and I do get questions about the site when they see how professional it looks, I'm sure out of those some will eventually join as they learn to grow out of their shells and seen the name "hive" over and over again attached to great wholesome content, that's what hive needs to focus on to get new users.
The way I see it, I live far away from most of my friends and relatives and it's a good way for those who want to keep updated with what I'm up to can with something more than just pictures. If many knew, hive can be so simply used, more will come for that aspect as well. Hopefully your next experiment works out and maybe you can get a few more to join our little eco-system along the way. Early adopters will be the ones to benefit the most.