Chiropractic manual from the 50's is still relevant.
Chiropractic is about sales. Little else.
Old chiropractic business manual uncovered
Software engineer Dan Kegel has discovered a 61-page manual from the Chiropractic Business Institute that appears to have circulated in the 1950s. The manual states:
"In addition to technique, there are four other factors of vital importance. You must also be a master salesman, an astute psychologist, a brilliant individualist, and an able business man."
"All doctors are naturally familiar with Diagnosis, but its interpretation means only the diagnosing of disease. Yet there is a second diagnosis of equal and vital importance. It deals primarily with analyzing a patient from a business standpoint, to determine his worth to the doctor."
Many of the sales pitches are geared toward (a) persuading patients to continue to have weekly care long after their symptoms have resolved, (b) undermining trust in medical doctors, and (c) promoting chiropractic for preventing as well as treating the gamut of health problems. The themes are still common in currently available chiropractic practice-building courses.
http://www.chirobase.org/20PB/chiro-business-manual.pdf