I'm going to respectively disagree. The experiences I had with being an intern I felt I was simply being used for free work. They treated me as if they were doing me a favor for school credit and had no interest in keeping me around. Everyone has their own experience though. Yours could be quite positive!
Start small. Get a job as a counselor at a ski camp and take that job seriously. Get other jobs at that camp so more people get to know you and you're skilled in multiple areas. Show your professionalism before you are one. Make connections in the camp and work your way up. Let it be known what your long term goals are. Advertising and marketing is a very important aspect of the camp. Show interest and talk to representatives that come to the camp for advertising purposes (photographers, videographers, journalist from magazines, etc.)
Develop a niche that will set you apart. For me, it was my self-taught graphic design. I was hired as a kitchen assistant at Lake Owen Action Sports Camp (a Woodward owned camp) in northern Wisconsin when I was 18. That summer I showed interest in designing their apparel line for free and volunteered my free time to helping the directors with other camp duties, etc, etc. I essentially social networked in real life. By the end of the summer I was promoted to the Assistant Director of Operations and was the boss of people twice my age. I have since worked at Woodward at Copper with similar positions. I've also done freelance design and marketing work for small companies like Girls on Skis. I've also worked as media for the Dew Tour the last two years and X Games last year. I get paid by my college to be the "student ambassador" and essentially market my life and their college experience by keeping up with a blog about my life.
I'm 20 years old and haven't even finished my 2nd year of college. I grew up in a small hick town in Wisconsin and didn't know ONE skier at my highschool. I now live in Breckenridge and ski everyday. My best friends are some of the best female pros in the industry and I have made some connections I could never even dream of.
If you want to get a good marketing job you have to do just that, market yourself. It's all about your enthusiasm, passion, creativity, and individuality in the industry. You have to be true and honest and approach companies and situations with the notion that you CAN do it, and not that you want the chance to learn how. But at the same time always stay humble. It's an industry that is constantly changing. You are never the best. There is always room to grow and learn and your expectations for return have to be close to nothing.
Overall, follow your heart.