Unbreakable Jars!

I had an epiphany.

Unbreakable jars.

There was never any "demand" for unbreakable jars. What happened is the price of plastic jars became cheaper than glass jars. The jar-packagers realized that they'd make bigger profits by switching to plastic, but needed a reason to tell the public why they were switching; because "Greater Profit Margins on dispensing the same amount of product" didn't have the same ring as something else... perhaps something like

"NOW IN AN UNBREAKABLE JAR!"

And that's why the "Unbreakable Jar" format, while yes, a good idea, became so popular!