Twitch has in general dropped the ball by not trying to make streams more interactive. I think we should be past the stage where we are using just "dumb" clients.
Would Twitch extensions fill this void? From what I know of the platform, it would let you implement interactive features.
Mixer has done interesting things in regards to interactive livestreaming. It seems like progress is being made towards giving users more ways to interact, it's just taking a while. Perhaps because we're not sure _what_ to make interactive?
