We usually associate the sales profession with extroverted, talkative and outgoing people. However, salespeople might have various personal qualities that may correspond to different types of customer. The big advantage introverted salespeople have is that they are often able to empathize with customers, build rapport and be discrete. Many clients prefer these types of salespeople over the flamboyant, extroverted ones. However, introverts have the tendency to lack self-confidence and to have doubts about themselves. Here are four pieces of advice for those who need to boost their self-esteem in sales.