It already exists as an informal social arrangement!

When I was a small child and caught chickenpox several of my friends were brought round to play so they could 'safely' catch it as children, rather than waiting to catch the altogether nastier grown-up version later in life.

I suspect my mother didn't charge for the product/service , although that may be because she couldn't get a node.js stack up and running.

Also it was in 1983.