As you can see under ‘Alternative and related questions’, there are many different ways in which can ask you this question. Regardless of how precisely they phrase themselves, you should aim to answer the question as if they had asked, “If I told you that I don’t think you’re the candidate we’re looking for, what would you say to try to change my mind?”
To successfully answer this question you need to have a clear understanding of what the perfect candidate for the job would be and how best you match that description – more so than the other candidates. But don’t go overboard in your answer; you probably don’t know anything about the other candidates!
This sort of question generally comes towards the end of an interview so if you feel that the interviewer’s previous questions have failed to cover one of your major selling points then now is the time to speak up or forever hold your peace.