The following blog post quotes are confirmation to me of my idea that the relevance of community is essential to viral adoption:

I had bugger all Facebook friends, and most of them were “lurkers” (they never posted anything or even “liked” anything, let alone made any comments. So meaningful interactions were few and far between.

About half of what few friends I had left on FB disagreed with much of what I really wanted to post about, so if I got into subjects like conspiracies such as false flag shootings or “climate change”, or health subjects like low carb diets or the vaccination con, its safe to say I rapidly had less FB friends.

That giant pool of Facebook users don’t post much worth seeing, so to me FB was like a giant sponge that soaked up every creative urge in my mind and replaced it with a giant sea of shallow distracting crap.

The biggest reason I quit FB was that I wanted to see new ideas and be inspired by intelligent discussion. That wasn’t exactly coming thick and fast on FB

The following appears to incorporate some amount of "we will change the world" backslapping because he doesn't even mention having tried Medium for comparison:

Steemit has already amazed me with the quality of the content. I’ve only been aware of Steemit for 48 hours, but I’m already inspired by what I’ve seen here, and I’ve learned more in two days surfing Steemit than I did in the past two years feeding my FB addiction.

What I think is inspiring him is he sees some of his interests are shared by the community on Steemit. The Steemit crowd is probably into the specific idealistic issues he mentioned. And there are some smart Steemians. But I believe this sub-community can also be found on Medium (but perhaps not as highly charged and massive)?

Any way, the point taken is that communities and size of network (connections and engagement) within the communities is essential, which is my point also.