Is this just my impression, or are we in a period where shows are regularly lasting a hell of a long time?
The Simpsons, L&O, ER, King of the Hill, South Park, Stargate (though I think that’s canceled), etc.
Actually, when I write out the list like that, it doesn’t look like a lot. But it does seem to me that shows are either being canceled quickly or lasting forever. Is there a statistical “average” for TV show survival?
Cartoons have a huge advantage over live action shows in that the characters never age and that they can be placed in a much larger variety of situations with breaking the “reality” of the show or the characters.
L&O and ER has lasted by changing the cast. I believe there are no original actors left on either series. Few other shows can get away with that since they are tied to their stars.
Cable channels can afford to leave shows on longer because they have less money to produce new shows and have less ability to attract really large audiences in the first place. The broadcast networks have a pile of programs they can plug in if the ratings get weak.
I think all your examples are exceptions that can be explained away. Nor is the phenomenon anything new. The all-time prime-time champ is still Gunsmoke at 20 years. The Jack Benny program lasted 15. Bonanza did 14. All in the Family/Archie Bunker’s Place lasted 13 seasons. MAS*H hit eleven. Popular variety series from Ed Sullivan to Carol Burnett to Red Skelton lasted forever.
All were exceptions, but were expected exceptions if I can use the term. That is, in all times and eras some shows will be statistical outliers and last for a very long time, but you can’t predict them ahead of time. They just happen.
Half of the shows you mentioned are animated. Animated shows can, at least potentially, go on indefinitely: you don’t have to worry about the actor who plays Bart Simpson or Bobby Hill or Eric Cartmen growing up. Plus, you don’t have a large cast who all have to be physically present (and dressed and made up) and the same time.
Other long-running shows have changing casts. They’re about situations, not specific people.
It’s not a new phenomenon or anything. An old example comes to mind: Doctor Who which lasted because they can easily change doctors willy nilly. 
Personally, I think it’s because there is so much new crap that hacks keep churning out that people will continue watch the quality shows…even after the quality is gone.
I think if you look far back there are plenty of old shows that went on a long time I mean Gunsmoke was on for twenty years and all in the family lasted pretty long.
The Ed Sullivan show did what, 20-25 years? What is it about variety shows lasting decades, but sitcoms are canceled left and right? Do people just get bored with sitcoms? I’m not sure Ed Sullivan would have lasted as long as it did without those shows with Elvis, The Beatles, The Rolling Stones, The Who, et al.
The Ed Sullivan show had to have lasted at least 20-25 years. He did well in the 50s, but I think his ratings would have tapered off and he would have been canceled if he didn’t reach out to a younger audience and have The Beatles, The Rolling Stones, The Who, etc… on his show.
sorry about the double post. :smack: