one doesn't know ahead of time which admissions officers will be reading one's application
At one East Coast university I'm familiar with, this is not true. Admissions officers are assigned geographic territories so the location of your high school determines which particular admission officer will be reading your application.
It's true that admissions officers are assigned geographic territories, though I don't know that the admissions officer from the territory is the only one to read one's application. One would have to go to heroic efforts to determine the biases of that particular admissions officer.
[Edit: The post below gives the impression that our conversations with admissions officers are our only reasons for believing the claims. We've also consulted with other sources such as How to Be a High School Superstar: A Revolutionary Plan to Get into College by Standing Out (Without Burning Out) which corroborate the admissions officers' remarks]
We spoke with admissions officers at Harvard, Yale, University of Chicago, Columbia, Stanford, MIT, Duke, University of Pennsylvania, Dartmouth, Williams, Johns Hopkins, Swarthmore, Brown, Northwestern and Caltech, about how they evaluate student participation in extracurricular activities, for 15 colleges total. Some things that we found based on college's statements are below.
Kawoomba suggests that colleges' statements on the first point below can't be taken at face value. What do you think?
Cross-posted from the Cognito Mentoring blog
See also High school extracurricular activities: factors to consider and College statements about extracurricular activities