Many an advertisement was for a practitioner, not a specific remedy. Itinerant healers in particular would print up a bunch of handbooks when they arrived in town, advising of their arrival, while established healers might also advertise in broadsides, or, more subtly in the prefaces to their books.
Evident satisfa[cti]on to the sick and lame; by Nath. Merry, student in physick…