I was unfortunately waitlisted to the faculty of Life Sciences about a month ago. I wrote a letter of continued interest (a good one) to the office of admissions and this is the reply I got back.
"Thank you for your recent communication showing your eagerness to attend McGill University. We appreciate your enthusiasm, but it is important for you to understand that such letters do not play a significant role in the admission process.
Your name is currently on a waitlist because of your demonstrated academic performance. In the event that space becomes available, you may be offered admission. That will be determined competitively on the basis of academic factors. At McGill, extra letters from applicants or their advocates attesting to interest does not factor into the admission decision as it might at other universities and colleges. Thank you for your understanding."
Is there REALLY nothing I can do to boost my chances? McGill is my first choice school and being waitlisted despite having a perfect ACT score is putting a damper on my college plans 
. Thanks