Pharmaceutical
Marketing
Tweet This Frank, is this an area where you have direct working experience? If it is not, you might want to look into the HIPAA laws, which cover patient privacy and confidentiality. I can see potential, given your description of this business, for it to potentially violate them!
See http://www.hhs.gov/ocr/privacy/hipaa/understanding/index.html (cut and paste...this system does not support live links) for a short summary of HIPAA -- from the consumer and health care provider point of view. I would think your business concept would fall under the same health care classification as pharmacies.