Sure, it's great at intermission when something important seems to be at stake, enough to make me want to return, but often the payoff takes preparation. All that exposition is the set-up for revelations that can only grab you when you know the characters well enough to care what happens to them. It's easy to break the spell, as a pager or cell phone accomplishes in an instant. I promise that, aside from unstoppable coughs, I won't let the actors know I'm there. Theatergoers are not unlike eavesdroppers who should fear detection.
Silence is still golden.
After a show ends, audiences believe that it's only polite to stand and cheer, if only to relieve our rears. But we owe the actors nothing but our presence. In real life, people don't get applauded, especially not if they mess up. Theater etiquette is good-hearted but inconsistent. No, not if you don't mean it.