How commercial variolators fought smallpox in the 18th century

See My Conversation with the excellent Sheilagh Ogilvie from Marginal Revolution. Excerpt:

"If you were a teenager in an English village in the 18th century and you were deciding, “I’m going to move to London and get a job,” you and your friendship group from the village would all go into the nearest town and pay a commercial variolator. You’d all get smallpox together. You’d go back to your village. You’d suffer through this mild case of smallpox, and then you would be immunized for life, assuming that you hadn’t died. You would go off to London and seek your fortune. It was very much a normal teenage thing to do.

There was this incredible franchising set up in England. It was like a McDonald’s, but to get variolated. There were these entrepreneurs who advertised themselves as having lower-risk ways of getting immunized and cheaper ways of getting immunized. There was this famous family of the Suttons that started a franchise in 18th-century England in the 1750s. Then they spread into the continent of Europe and actually into North America."