Companies like Facebook, Twitter and even Google learned it long ago. Humans are a much better product than anything the industry itself can create.
Verizon knows it and this is the result. They can get away with these tiered low cap crappy "plans" because they are no longer selling you anything, they're buying you as a product to continually feed money into the corporate bank account at the lowest price to the them.
Humans are the commodity and the "service" is incidental. They're attempting to strike that perfect balance between consumer hatred and consumer apathy. There's a line at which their service becomes so shitty and abusive that they start losing customers and they know that so they pull back just before, like stretching a rubber band to it's absolute limit before it breaks.