Rather rarely does someone actually end up working in the same field as their 4-year degree, so don't look at this as the end-all. Maybe you will graduate initially working in your field, but today's worker will go through 12+ job changes throughout his life, whereas in my Grandfather's day he could count on enduring maybe 2 job changes. If that.
Your college education is a foundation upon which you will build the rest of the house for the rest of your life. It is in college where you learn how to learn. Acquire the fundamentals and fluency of communication, economics, society, business, science, and the like. It is where you will learn balance in a more "adult" life than you have been living to date.
If you plan on working in any sort of business -- which obviously you will be, given that you're looking at marketing -- I recommend studying business. It is a foundation that you will always be able to use, it'll never leave you high & dry. It is both universal and essential. It is so much easier and cheaper to learn business essentials in school than to spend thousands of dollars (or sacrifice much more) to learn the principles the "hard way."
If you're looking at marketing, the key principle behind any sort of salesmanship is COMMUNICATION. You need to be able to spell, write, make presentations of all sorts, speak comfortably... a communications background will be a cornerstone to whatever semi-related line of work you choose downline. It doesn't have to be in marketing or sales. Say, perhaps, that at some point you end up in middle management at a health benefits company. What are two keys that you will need to kick butt in that role? A solid grasp of the business world, and excellent communication skills. These are just 2 things you can't go wrong with.
You will learn
how to learn in college. It is only the start of a lifelong journey of learning. Whatever industry you end up in after graduation, you will be able to teach yourself/"pick it up" pretty quickly with a solid educational background under your feet. The resources online are mind boggling and are growing in volume every day. It'll still all be here when you get out of school... in fact it will have grown tremendously.
Good luck in college. And above all ~~ have fun!!!

Bailey