Interesting...Rudolph was animated via "Puppetoons" - a stop-motion style of puppetry, while "Frosty" was animated via traditional 2D limited animation. Both were so well-done, that, 50 years after their debut, the two specials still get stellar ratings, according to the Hollywood Reporter:
(Rankin's) holiday specials air every year and always draw a crowd. In December, Rudolph the Red-Nosed Reindeer, which debuted in 1964, and Frosty the Snowman, which premiered in 1969, were broadcast by CBS and were the two highest-rated programs of the night.
The key to the specials' success is twofold - first of all, both were based on memorable Christmas songs. Secondly, the scripts of the two specials were top-notch - witty, insightful, poignant, and best of all, they didn't talk down to children.
It all begins with writing, kids. Clever drawing will not rescue poor prose. I'm still so impressed at how Rankin and his partner, Jules Bass, extrapolated and improved upon the original Rudolph story (which, in its original incarnation as a promotional give-away storybook for the now-defunct department store chain Montgomery Ward, was written in rather forced and clunky rhyme by Rudolph's creator, Robert L. May), and gave it a resonance that endeared it to generation after generation. The same deal with Frosty: how many of us fell in love with the cuddly snowman, only to have our hearts broken by his apparent demise at the hands of the devious Professor Hinkle?
Rudolph and Frosty were an important part of my childhood, and since I'm still pretty much a kid, they'll always be a part of me.
Goodbye, Mr. Rankin. The child in me weeps.