So lately I've noticed that the people who come out to see stand-up comedy can usually be categorized into several groups. From a comedian's perspective, some of these groups include:
This guy will be sitting in the front row, directly across from you. He doesn't like you. With his arms crossed for no real reason, he just stares at you angrily, daring you to make him laugh. Don't call attention to him directly; he probably has a super hot girlfriend right beside him, laughing her ass off. Hit on her. Shortly after, make a remark about getting your ass kicked in the parking lot. This will probably actually happen.
The Focus Group
Most of the time, this group consists of 4-6 women sitting together. After every punch line, they will turn to each other and discuss, with a series of whispers, how funny or offensive it was and which friend of theirs it reminded them of. Only afterwards will a proper reaction to the joke take place, regardless if you're on to the next one or not. Try to time their laughter so that it comes after something inappropriate, like puppy molestation. Works every time.
This guy has seen your act before, and has come back for a second time except not on purpose. He doesn't know you by name, and barely recognizes your face, but apparently he has every single one of your bits memorized. You'll hear him ending most your jokes for you to his group of friends, plus whoever else is sitting by them. Talk faster to beat him to the punch, and afterwards, literally beat him with a punch. He can't step all over your punch lines if his jaw is wired shut.
The Lost Soul
The fact of the matter is, this guy just needs someone to talk to. He somehow feels a strong connection with you from the start. Everything you say "is so true", and he often knows "exactly what you're talking about". He totally does. He's not even laughing, but instead spends the entire time agreeing with you out loud. This is most likely the same guy who will try giving you material after the show, and tell you stories about his personal life to use on stage. Since his friends have apparently left without him, be ready to turn down a request for a ride. He can use the time it takes to walk home to think over his sexual preferences.