[mrweasel]

Technically I don't think it's unique to the US. In Denmark doctors get a fee per consultation. It's pay with tax money, but still the doctor is financially motivated to see patients. It might only apply to general practitioner though, I think hospital doctors are on a fixed salary.

One issue, that could excuse medical companies going directly to the patients would be a lack of knowledge among doctors. Doctors contently write prescriptions for medication that's no longer available and is often not as updated as a pharmacy on new medication. This means that at least some doctors aren't suggesting the best treatment, simply because they aren't aware of it.

[varispeed]

The doctor can also put a generic name of the drug on the prescription and patient can tell the pharmacy to sell them a particular brand instead of a generic. So there is space where such direct advertising could work.