I"ll post the opposite view about letting programs know you're interested - I've talked to many program directors about this last year, as well as my own PD states it over and over again to applicants:
you should strongly consider telling programs where you want to go, that you want to be there.
all things considered, you interview 100 people for your program and you're trying to decide between putting MR. X at 14 on your list or 15...or 22 or whatever. You think similarly of Ms. Y and having the same question: where to put her on your list.
wouldn't it influence your decision as a program director if you knew that Mr. X had told you, and made a good case as well, that he really wanted to be at your program?: "I know, Dr. Smith, that I would be very happy at your program and honored to be there. I'm so convinced of this that I plan to rank your program among my top 3 choices and would appreciate any consideration you can give me as I would be very happy to be at your program in July."
Ms. Y on the other hand has not contacted Dr. Smith at all: " I figure that they'll rank the best, and I'll rank the best - why contact them as it'll all work out and won't be an influence," she says.
In our program Mr. X would go up on the list - "he really wants to be here! Great, we really want him too!"
Ms. Y would similarly go down, comparatively speaking, on the list - "we've not heard from her and I think she's not very interested."
There are plenty of people on SDN that will disagree with this view. But - look into your future: if you are Dr. Smith - the exalted EM PD of the future, wouldn't you be influenced by those who wanted to be at your program relative to those who had not indicated a sincere interest? I hope so, or at least I hope I"ll see the world that way if I'm ever a PD - which seems a long way from the intern year, I tell ya.
Also, in my own little world, I would rather train with Dr. Smith the program director that is influenced by people and their stated desires, instead of Dr. Smith the program director that is driven by the numbers on the ERAS applic and the all-knowing 5 hours they spent on interview day, etc.
It's a matter of opinion and I've stated my case for the opposing side, which I admit is influenced substantially by my experience in the match last year interviewing at alot of programs as well as the views expressed by my program director to applicants at our place. I respect the views that you should keep your cards to your chest and that it won't influence programs - but these are not places I'd want to be.
