"As a marketing intern, you must come with the attitude to support the marketing department, but also the understanding that you are there to acquire experience. In your interview, be sure to emphasize your analytical, advertising, and interpersonal skills to make for a good candidate. Expect to be asked about any of your previous sales experience, how you can contribute to their team, and potentially role-play a situation where you must sell your interviewer a product."
Nothing tricky. Asked why I wanted the job, and how I was qualified.