Whose business is it on which medications you take? Apparently, if you ask the pharmaceutical companies, it is their business.
The article I cited is written by a doctor who would like to see doctors sign up with the AMA to prevent their prescription data being sold without their express permission. I am writing from the side of marketing and as a patient.
In the real (non medical) world I do marketing for a living. In a perfect marketing world, for every mailing that went out, there would be a sale. But that isn't how it works - we all open our mail over the shredder and hit delete on our email without reading it. So pharmaceutical companies use the prescription data - from pharmacies with the patient names but not the doctor names removed - to refine their marketing. It is in their interest to promote newer medications which are still patent protected and will reap the larger profits.
As a marketer, I can see the value of knowing doctor prescribing patterns. A doctor who prescribes new medications and tests regularly is a good target for marketing of new items. But a doctor who isn't as receptive to change is not. Also, the data will tell pharma companies what kind of patients the doctor really treats - also very valuable. This is the dream of marketers - to find out what people really prescribe so they can target their efforts.
As a patient, I don't really care what the pharmaceutical companies thinks or what marketers want. I want the doctor to prescribe what I really need, not what the marketers from the pharma companies want them to prescribe.