The summer before senior year in high school is the right time for students to apply to college. They shouldn't wait until the last minute, as they will then have to rush the application process, as is so often the case.
Some students, namely those who feel confident that they're already academically and monetarily prepared, can apply to college early. This usually means they know exactly where they want to attend; therefore, there's no need to delay matters. Such students possibly have a better chance of getting into the school of their choice than someone who waits, and the school they've chosen will give them an early decision.