For example, when we want to tell HN users of Postatic, the most effective way we found was to tell them that they can create their own HN site.
I guess for Reddit users, it would be better to target it as "create your own Reddit".
"Community" is good, but there are a plenty of sites that use that word and we also need to stand our.
So right now, we're displaying what's been working the best according to the data - surely it'll evolve.