What about those who have sent a letter of intent and frequent updates? Or would that be less of a determinant than the above factors? Thanks!
Applicants should not send "frequent" updates. In the early and mid part of wait list season, our school assumes that unless we know otherwise for an applicant, all of the applicants are interested in getting into our school off the WL. (We will not of course know where the applicants have been accepted, so it may be a bit more unknown than in the past).
Certainly, follow any explicit rules - if the schools tells or suggests that you to send them a letter of intent or continued interest to maintain on the WL, by all means do so.
And if you do have a significant update (spring term grades, esp if phenomenonal, or publication, award), then certainly you can send an update if permitted.
What Goro and I were saying was that for that very slow trickle at the very end of the season, as school is about to start, the Dean of Admissions may need to get creative in terms of whom they select, and they are relatively free to choose from the WL pool, and they may use whatever they want to ensure greatest probability that applicant will say yes and show up immediately. LOI's do not usually work because way too many WL students send these to every place they are put on WL. And if one has sent "frequent" updates, one might be remembered in a negative light by the Admissions' Dean. I would say that especially if you are higher stats for a given school, holding acceptances for what might be considered "better" schools, but you would take a spot at school X bc it is so much a better fit for you (ie geography, mission, etc), then you might consider a well-crafted update letter (that also includes a relevant update or two) that describes why you would choose school X over the other schools to which you have been accepted. This could only be done for one school and must be 100% honest. It is likely not going to make any difference and this is only for that very slow trickle of spots that MIGHT open up as school begins.