I think that a lot of people are worried about the cost of brand-name drugs, as many employer-sponsored health plans seem to be reducing their prescription coverage.  This is probably having as much effect on people not asking for drugs by name as anything.

I do think that brand-awareness direct-to-consumer advertising is probably still a good deal for pharmaceutical companies.

First, when a doctor says "I'm going to prescribe XX for your complaint," the patient may have a friendly association with that drug given the many ads she's seen.

Second, they help to sell the "category" of the particular complaint (sleep deprivation, sexual dysfunction, social anxiety, hayfever).  As with Listerine's halitosis ads of the past, many of these ads manage to create a perception in the consumer that she's got a problem that previously she didn't think was actually a problem.  She goes to the doctor for relief, and the doctor may very well prescribe the drug.  Unless a person goes to her doctor, she can't get the drug anyhow, so this is an important part of the marketing and sales.

But any direct-to-consumer marketing pales in importance, I'm sure, compared to the relatively unregulated efforts in wining and dining and shamelessly courting doctors with freebies, which I suspect is how the drug manufacturers really push their prescription drugs on the public.

PS It's too bad the study apparently didn't break out the requests by different drugs -- I'd bet a lot of money that Viagra is the #1 drug asked for by name.