Visiting schools is very important when it comes to learning about the schools. That said if you dont visit it isnt going to mean an automatic ding. Some schools definitely put more emphasis on visits than others, these are typically more rural settings. The one way it looks very bad is if you live within driving distance but never go to the campus.
Interviews on and off campus are pretty close to equal at most schools. I am of the opinion that at most schools interviews are not very important, the majority of decisions are made regardless of interviews. Look at how many people here get in despite having terrible interviews but get dinged after having a great interview.
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Kellogg Class of 2010...still active and willing to help. However, I do not do profile reviews, don't offer predictions on chances and am far to busy to review essays, so save the energy of writing me a PM seeking help for these. If I don't respond to a PM that is not one of the previously mentioned trash can destined messages, please don't take it personally I get so many messages I have a hard to responding to most. The more interesting, compelling, or humorous you message the more likely I am to respond.