I know it seems obvious. Most comics know that this is the most obvious thing in comedy. But those that do not, well, they REALLY do not.
The light tells you when your shift is over, and you NEED to respect that. Running the light is the quickest way to never get booked again. Some comics might think “yeah, but if I am killing, I’m helping the show, so fuck the light.” Here are the reasons why you’re terribly, terribly wrong.
1) Consider the other comedians. Every minute you go over is a minute you’re stealing from someone else.
2) Consider the balance of the show. When you think about how hard you’re killing or how your bit isn’t finished – are you thinking about the show as a whole? The balance of different types of comics? The arc of the show? These are things good producers consider when they book you.
3) Consider the staff. They are tired. They don’t want to be held hostage by someone’s ego. Without a happy staff, a club can’t operate. Every time you blow the light, you push a server that much closer to quitting. The staff keeps quitting, there is no club. Then you won’t even have the chance to indulge your ego at the expense of others. “Yeah, but that one waitress told me she thinks I should go longer.” Did every staff member say that? No.
4) Consider the crowd. The best way to get returning customers is not to drown them in comedy, but to leave them wanting more. Trust the club to know when that is.
5) Consider yourself. You do NOT want to have a reputation for disrespecting the club and other comedians. It doesn’t make you a badass, it makes you a selfish prick. Treat others how you want to be treated – both your peers and your bosses.
You are not an avant guard performance artist. If you were, you’d never charge for anything. You are a professional doing a job – and need to act like one. That’s the way you get to keep having this job.
I hope this helps.