Well, we're pretty much everywhere that we think matters!
One of our most regular social media channels is Facebook, where various team members contribute to the maintenance of our TEDxCalgary page. That's one of the places -- apart from our newsletter or website -- which we'll normally use to announce new events, share perspectives that we think may be of interest, and post updates about our various event talks.
We also have Twitter and Instagram accounts that we use for shorter messages, and more visuals.
If there's a place you think we should be and we're not, let us know by filing a support ticket... in this case, we appreciate YOUR help!