This is an important question that you will need to answer carefully. It is your chance to stand out and draw attention to your skills, especially those that haven't already been addressed. Saying "because I need a job" or "I'm really good" just won't cut it. Don't speculate about other candidates and their possible strengths or flaws. Make sure you focus on you. Explain why you make a good employee, why you are a good fit for the job and the company, and what you can offer. Keep it succinct and highlight your achievements.