Verizon JetPack Unlimited

A friend of mine across the border in the States has something called a Jetpack, which is basically a wifi hotspot that you can connect to and get wifi across the Verizon network. His speeds are at what they call 4g Lte, so around 12 mpbs.

He pays $200 for unlimited data, he uses it for work, mostly in his car while traveling and he loves it.

He told me he has to pay a guy (not the provider itself for this service) since this service is not available via verizon.

I guess my question is how does this service work?

He told me it will not work in Mexico or Canada and only in areas of verizon coverage for cell phones.

Guess I am just curious how this all works, are they using old plans that were grandfathered in or is this something totally different?