I digress - most cartoon series these days last for four seasons, and a total of 52 episodes
That's how it was a few years ago. Now things have changed. If something isn't an instant success, or it doesn't keep its funding, or a TV channel drops it's kid's line up (CW for example) a cartoon won't even last a full season. Maybe 2 seasons... But all before their time. Spectacular Spider-Man is apparently getting canned after the second season (no thanks to Sony and the CW for dropping its kid's programming, as mentioned earlier).
Spongebob has been on 10 years, and it wasn't really successful until the second season. Had it premired let's say this year, we would have seen half the first season, and then it would have been canceled for another one of those grasping at straws Saved by the Bell clones made to compete with Disney's Saved by the Bell/Monkees clones with no real fight. We're never going to get a long lasting cartoon that impacted like Spongebob... or even Fairly Oddparents again... unless there are drastic changes to kid's television. And the fact we've been in a recession hasn't been helping matters either.
Nowadays, you can't even sell a cartoon unless it's guaranteed to be a smash success toy/marketing money maker... and with kids not buying toys, they're nailed into the wall there... and of course, all the other things I've been ranting about the past 2 years.... Something's gotta be done. Not so much that I can get work, but Kids NEED a childhood. We care more about our childhoods than actual kids care about theirs. They just want more "Mature" things like cartoonish acting people in live action series, not "Kiddy cartoons for babies." (i.e. anything that they aren't supposed to watch...Family Guy, South Park, adult swim...)