The other advantage in scheduling tweets is, when I am live at the event, instead of having to type out what I have to say, I can concentrate on retweeting and conversations. It's time efficient. Not so many of you know, but I'm dyslexic. It takes me half an hour to schedule tweets, that would be half of the hour wasted if I typed them in live.
I didn't realise scheduling tweets was a secret, doesn't everyone do it? Otherwise, how is it possible to keep up?