Rarely do candidates come to the end of an interview feeling they've done their best. Maybe the conversation went in an unexpected direction. Maybe the interviewer focused on one aspect of their skills and totally ignored other key attributes. Or maybe candidates started the interview nervous and hesitant, and now wish they could go back and better describe their qualifications and experience.
Any candidate can read and regurgitate the company’s “About” page. So, when interviewers ask this, they aren't necessarily trying to gauge whether you understand the mission—they want to know whether you care about it. Start with one line that shows you understand the company's goals, using a couple key words and phrases from the website, but then go on to make it personal. Say, “I’m personally drawn to this mission because…” or “I really believe in this approach because…” and share a personal example or two.