The other day, I started thinking about working in a mirror factory; that type of work is something that I can totally see myself doing. The only company I will work for is one where I'm ignored, left to my own devices, and provided unlimited Internet, coffee and doughnuts.
People enjoy one- to two-line jokes for two reasons. The first is because it's a quick way to make people laugh. The second is because they are easy to remember. While jokes that are longer than one to two sentences or lines can be just as funny, they always require additional time to tell, sometimes require more theatrics and can be harder to remember. The last thing you want is to tell the joke wrong or say the punch line incorrectly.
Additionally, when engaged in conversation, you can easily insert a short joke when appropriate, and then smoothly transition back to the original discussion. If you tell a longer joke, the people you are conversing with may lose their initial train of thought or think it rude that the conversation was interrupted to begin with. Use your own discretion on whether a short joke should be used compared to a long joke. Longer jokes may be more appropriate when you're with good friends, family or other people that you are close to. Shorter jokes tend to be more appropriate for a work setting, such as meeting with business partners or clients or for social gatherings where you are surrounded more by acquaintances than close friends and loved ones.