Originally Posted by
Powerboy
Good point. A couple of decades ago, you could substitute Barney the Dinosaur for Sponge Bob. But Barney has faded. He appealed to a generation of small children and didn't transcend that generation. The same thing seems to be happening with Sponge Bob.
As DochaDocha said, lots of luck. Some characters become popular because they came along at exactly the right time and, by the time that era faded, they were burned into the public consciousness. Great marketing, a set of lucky coincidences, a touch of originality. It's unpredictable.