This question sets the stage for highlighting your positive attributes as a sales rep. But when put on the spot, it can be hard to elaborate on exactly what motivates you. Don't give a generic or vague response. This is a personal question, so you'll want to dig deep and answer this.

Use this question as an opportunity to provide insight into your character. Are you motivated by goals, pleasing your employer, or being among the highest performing sales reps? This lets your interviewer know whether you'll be a good fit in the company and how to motivate you if you're offered the job.