People come to see my show with Cirque du Soleil, "KOOZA" and they Tweet before,during, at intermission, and afterwards. I am one of the three clowns in the show and we often read what people are Tweeting about the show for a laugh. The show is phenomenal so most comments are positive. We also use audience members in our act and our volunteers sometimes tweet their experience or post pictures on Twitter.
It's weird, to me, randomly picking a person out of 2,500 people and when you've sent them back to their seats and the show has finished, reading their Tweets or knowing their names! (I'm still adjusting to this- I like the anonymity..)
Recently someone who was watching the show put up on Twitter how incredible it was during the show. We read it and saw his other Tweets were entertaining and passed it around.
This guy has a small group of friends, (under 30 followers) obviously close friends from school, and now he has opened himself up to a huge network of circus performers and artists only because he typed something about the show. In some cases people don't "Follow" you they just read what you write by bookmarking your page. (So be-careful what you posting to an "intimate" group...because with Twitter the world may be watching.
By the way, in the second act of the show in the clown act I quoted one of his funny Tweets word for word at a silent moment in the act. I still wonder if that one random guy heard my direct interaction for him out of 2,500 people watching that night. Truly interactive technology and state of the art comedy.