Social marketing, Id go with:
1. Ability to learn and stay on the cutting edge of new technologies
2. Superior technical skills and the knowledge on how and where to find answers
3. Time management/ability to juggle multiple programs and platforms
Have you done this work professionally before? I had an interview last week ask for specific social media accomplishments. I had none other than my shitty facebook page. If you have concrete examples, print em out. Send links. Do whatever you can to build it up. If you have no experience, well, its REALLY hard to BS this one cause they can type in two words and find it out. good luck.