it had to keep pushing it.
I remember a old episode of Buffy the Vampire Slayer. There was a random joke based on umpire sounding like vampire. Nothing hillarious, but it might give you a light smile. Or it might not. Regardless it was a one liner that took 2 seconds.
Mad TV did the same joke, I guess not knowing the show they were doing a parody of already did it themselves. Went on for five fucking minutes.
The only decent sketch type show I've seen is Robot Chicken(Not live action, but same basic deal). It's not just good because it's got good writters, Mad TV or saturday night live could have good writters and still suck. It's good because it's SHORT. The problem with sketch shows is they have too much time to fill. They kill themselves extending jokes for time and, even worst, by having recurring characters.