Twitch has a cool feature for streamers, where the longer a viewer watches a stream, the more "Stream Points" they get. This is a great way to get a channel's viewers to interact with the streamer, since that encourages viewers to talk more in the chat.
About every 5 minutes you get 250 points, and the streamer can add rewards costing however much they decide it costs. This could include something like dancing to a silly song for the viewers for maybe 10,000 points, giving the viewer a VIP badge for 20,000 points, or something small like a posture check, so the viewers make sure the streamer isn't slouching too much (full time streamers stream sitting in a chair for hours and hours strait). I'm currently working on adding my own fun channel points, and I'm even taking suggestions from friends and some of my viewers.