Our discourse community is a forum for the commercial and free RemObjects products at https://talk.remobjects.com; it’s where we deal with customer questions, general discussions, bug reports and feature requests.
We started with a public community to replace our previous forum Vanilla forum somewhere in October 2013, after a trial setup before that to move over the older posts. For the public part of our forum we get between 25 and 35 topics a week, with 200 - 250 posts a week, some of those are support; for the private support we get about 30-40 messages a week.
Originally we used a custom solution for support and ZenDesk for sales, where the custom solution was a bot that stores a the support mail and it’s replies in a bugtracker. We tried several others like otrs and phphelpdesk but didn’t really like any of them. When the private support features were added and after a few fixes/tweaks from Discourse we started using Discourse for both, the timing for that feature was perfect for us as we were actively looking for an alternative, and were already using Discourse for public support. The big advantage here was that we have a clear way to find and search support related issues. Other than some minor missing issues (like some form of easily discover able “Awaiting reply”) we really discourse as it gives us a single place where all our support and product specific questions are stored.