In any business organization, the sales reps are very vital, and their roles cannot be underestimated. They can be seen as a bridge between an organization and the customers. In fact, I would say they are like the entrance of customers and money into the company.
However, a serious challenge that a sales rep can face is identifying a customer's identity because they just need to do it. As it is very important for you to as a sales rep to make use of your experience and previous knowledge in your career, still you will always have new encounters every day with new customers.
One very important thing that you should learn to do is listening. Don't overtalk your client; allow them to do more of the talking, pay attention to details, and read words in between lines. Nevertheless, if they ask you questions, do your best in attending to them. Also, you should also not assume, but learn to ask questions.