The interviewer is interested in knowing if you have any marketing or advertising experience because these skills could be useful for the job you are applying for. Having expertise in these areas could indicate that you understand how to promote products and create effective campaigns. However, even if you don't have direct experience in marketing, advertising, or market research, you may still have relevant skills, so make sure to highlight those during the interview.
Talk to the interviewer about any experience you have in advertising and marketing, whether that be on-the-job training or formal education. Discuss how you have seen robust marketing strategies directly affect the performance of a product, using a personal strategy as an example if you have one.