> How does it seem like the ad was superfluous?

just to be clear i don't know your friend or their life or their medical condition or if the drug you saw an ad for treats their condition or if you saw an ad for a drug or if your friend has a medical conditon or if you have a friend at all... and i don't know if every event in a chain of events is necessary to the eventual outcome of that chain of events... and i can't see into the alternate reality wherein you didn't see that ad for a drug, to know your friend would've been fine in the end... and so on.

i'm speaking more generally, saying advertising is superfluous to medicine.

By accepting SWAG from the pharma rep, or accepting free trips to conferences sponsored by pharama. If a doctor has not heard about a new drug the their reps just haven't made their way to them yet because they're in a smaller market. The yet is key, eventually a rep will make their way to them. More than likely much sooner than the TV ads run

By researching new drugs? Though sadly at the moment the doctor is also a target of advertising. The point being that this should generally be a pull process driven by a demand (and mediated by neutral review and publication processes) and not a push being driven by a supply (mediated by a process that goes to the highest bidder).

so in your mind "advertisement" covers any transmission of information?

ah the world where ads are a good form of education.