Usually, I buy snack food for the taste. With Screaming Yellow Zonkers, I bought them for the box.
Not that they were bad. Screaming Yellow Zonkers were candy-coated popcorn -- like Crackerjack without the peanuts and the prize. Since I didn't care for peanuts, and the prizes in my day were cheap plastic toys about the size to choke a two-year-old, that meant they were the best part.
And then there was the box.
Like the Morning Chex Press, the box was covered with strange and witty comments. My favorite was at the spot where grocers stamped the price: "Easily cheaper than diamonds of equal weight." There were oddball lists and strange directions, like the words printed on the bottom of the box: "This might be the bottom of the box. To find out, open the top, and turn the box upside down. If the Zonkers fall out, this is the bottom. If they fall up, this is the top. If nothing happens, this box is empty.”
The boxes also featured cartoons and oddball art*. It was as much fun reading the box as it was eating the food. And the boxes changed every few months, giving you a reason to buy more.
They also has some impressively strange ads:
Addendum: Good News! (4/18/12)
*It's also billed as the first product to use predominantly black packaging. That may be so. It was tricky to print all black; you had to cover the package with black ink and the white-on-black text required it be done perfectly.