Advertise 'TED Conversations' so that more people are aware of this section of the site.
Many threads are opened, the vast majority receive few/no responses unless they're promoted on the first immediate page for days-weeks at a time and even most of those comments are from sub-discussions between 2 people.
Conclusion: There are simply not enough people aware of this part of the site.
Goal: Have TED promote this part of the site on its videos.
Eg/ Annotations, details in description box or a video.