Let's say you're a bachelor, and it's been a while since you've been on a date. So you put up a profile at OKCupid, send messages to a couple of girls who catch your eye, and one of them responds that she would love to meet you for dinner. After a lovely dinner of spaghetti carbonara, your date takes a sip of ice water and asks flirtatiously, "So, why did you ask me out?"
You're caught off guard, because really, she was just the first attractive person who said yes to you. "Uh, I guess I thought you would go out with me?" Crap, that's not what you meant to say, so you try again, "I mean, you look like you would go out with me.. You're not that hot, but I'm not either, so we seem like we're a good fit." Your date throws her water in your face, grabs her purse, and leaves.
What does this have to do with applying to medical school? In our example above, the boy chooses a date the way most pre-meds choose a med school. Most pre-meds apply to the schools where they think they can get an interview (i.e. just by comparing their MCAT and GPA to the school's averages) without considering why they would potentially choose that med school over all of the other med schools in the United States. And medical schools, like your date, only want to go out with you if you have a specific reason for choosing them. When it turns out that you're not thinking with your brain, well, they reject you.
For every med school on your list, you will need to answer the question, "Why did you ask me out?" You will often be asked this question on secondary essays (e.g. "Why our school?"), and you will have to answer again when you go in for your interview. That means you must answer an important question for every school on your list: "Why would I choose to attend this medical school even if I get into several equivalent schools?"
For example, if you get into Albany, Rosalind Franklin, and New York Medical College, why would you choose Rosalind Franklin? You need to have several (at least 3) solid reasons you like the school so that you write a compelling "why our school" secondary essay. You will also have to be so convincing that you can reiterate your answer in person during an interview.
You could imagine several good reasons to choose Rosalind Franklin:
It's not that each of these reasons is only unique to Rosalind Franklin - indeed, there are plenty of medical schools in Chicago and many more that give you early clinical exposure and have solid neuroscience programs. But the combination of these reasons is hard to find, and it's clear that you haven't just picked Rosalind Franklin randomly from a list of medical schools with your GPA and MCAT.
Back to our date - imagine how differently our date would have gone if our hero had said:
“Well, the first thing that drew me to your profile is that you have nice eyes. But when I read a little more I was intrigued. We both really like hiking and camping, and we seem to want the same things from life: adventure, a big family, and spending time with people we love. Plus, you like the Pixies, who are my favorite band.”
It's a charming mix of big picture (life goals), small picture (favorite band), and obvious (you're attractive). But it shows your date that you've taken the time to consider her and get to know her, and that's exactly what the med schools want too. So before you apply, really research the schools on your list. It will make you much more likely to get in.