You probably aren't hearing anything because you aren't involved with the school at all at this point (not a current applicant/student/alumnus).
I did this a couple months ago per the suggestion of one of my M4 friends and included my AAMC id number. I got one response that was all of one line. I would still recommend contacting them though, you never know who is looking at what, no matter if you get a response or not. I think those emails were why I got some of my interview invites.