You’re at the doctor’s office, and you see strolling up to the window a good-looking, well-dressed professional. They’re usually pulling a little discreet cart, and after a few words with the receptionist they’re rushed right back. Sometimes they’ll bring a tray of cookies, or they’ll be followed by a caterer with a cartful of food.

You think they had an appointment? No, but you can be they’re here to see the doctor.

Take a look at this wonderful — and very dismaying — article from PLOS Medicine, written by a physician and a former pharmaceutical sales rep. The practice of detailing, or in-person visits to doctors ostensibly to provide medical information on the latest pharmaceutical products, is a many-billion-dollar industry aimed at making sure your physicians prescribe what the industry wants them to prescribe. Hint: it’s the newest medicines with the biggest profit margins.

So what if the newest medicines aren’t the best for you?

You really ought to read the article. Summarizing it just won’t do it justice. You’ll see what specific techniques the reps use, and how they get the data they need to influence the doctors they’re pretending to befriend. I’ll just post one quote that sums it up:

“While it’s the doctors’ job to treat patients and not to justify their actions, it’s my job to constantly sway the doctors. It’s a job I’m paid and trained to do. Doctors are neither trained nor paid to negotiate. Most of the time they don’t even realize that’s what they’re doing …”

I’ll tell you that when the subject of drug reps comes up among doctors, most are offended by the very idea that we’re being manipulated. We think we’re far too smart for that — a bagel and smile isn’t going to change what we do. All those years of training insulate us from the effects of crass marketing, right?

Look, if it didn’t work, they wouldn’t spend billions doing it.

At my office, we have a strict policy: the reps drop off samples, and that’s it. No talking to docs, no food, no gifts allowed. I’d rather honestly go without the samples, but some families really do need them. Perhaps even allowing that is allowing the reps to go too far. I know I’m not immune. Is your physician?

Roy Benaroch is a pediatrician who blogs at The Pediatric Insider. He is also the author of Solving Health and Behavioral Problems from Birth through Preschool: A Parent’s Guide and A Guide to Getting the Best Health Care for Your Child.