You find that most schools like to ask for an explanation of why you are interested in attending their school. Were you thinking about that essay when you began narrowing down your list of schools to which you were going to apply? You should have been if you want to improve your chances of admission.
This is the second year in a row college admissions officers have told me that application essays, as a group, were pretty disappointing. They use phrases like "they're writing too safe" and "we appreciate the effort," but what they mean is clear; they were given celery when they were looking for steak.