I think there are so many users who never visit this forum, and the amount that visit here is a thousandth fraction of all user base. Why don't you use Google+ communities for this purpose? I think much more people would join discussions. To me most people hate registration process, but almost everyone has a google account already, so they will have less drawback to participate in discussion.
Google+ would be good for raising awareness of this app too...
Thank you for your suggestion!
We are using those forums as they integrate very nicely with our help-desk system so we will not be setting up new ones for now.