The numbers were roughly based on aggregated values across all our current partner companies working with us. Most of these orgs have not imported their historical data either, however they all have added support for integrating their own custom auth services into Talk, as that whole layer is pluggable, hence you might get most of the users auto-added with low participation.

The ease of use of the moderation system as well might mean that more bad comments are pushed out of the system, making it full of more higher quality discussions.

One of the pillars of Coral is to provide lots of research to assist orgs develop community strategies[0], I'd suggest taking a look if you're interested!

[0]: http://guides.coralproject.net/