The best answer a person can give to such a question is telling the interviewee the contributions he or she is going to make while working in the company. Stating the experience and other skills to support the answer can also help.
When accepted for an interview, a person needs to do research on the company before the interview. Mission statement, product information, financial statements and founders' information are some of the things a person should strive to learn about. In addition, a person should understand his or her skills, background, strengths and experience as this helps in giving the right answer to the question.