Week 1. Send in LOI
Week 2. Call one week after you sent it via snail mail to see if they received it.
Week 3. Send in another LOR from a prof. or employer or M.D.
Week 4. Call one week after you sent it to see if they received that and inquire about your status or if there were movement on the waitlist.
If your grades were good fall semester, send those in ASAP with the LOI.
To the admissions staff, this is a game. Everyone on the waitlist has the around the same grades/mcat scores and they want to see WHO will speak the loudest to let them know WHO is 100% interested.
How to play the game: Keep making the admissions office open your file every week so they become familiar with your name. They document every call or email and add it to your file. NO LIE!!!! When they need to pull names from the waitlist....it only makes sense to pick YOU over the person who didnt send in one thing. Think about it?
You have a really good chance and once you get in off the waitlist...it is an even greater accomplishment and you understand how to work the system and how it is worked.
Good Luck and let me know if you have further questions.