What skills are essential for effective sales in customer service?

The skills of rapport, empathy, questioning, and listening are fundamental to effective sales in customer service because they directly contribute to building strong relationships with customers. Establishing rapport allows a salesperson to connect with customers on a personal level, creating a sense of trust and comfort. Empathy is crucial for understanding the customer's feelings and needs, which can guide the conversation and help tailor solutions to individual problems.

Questioning techniques enable sales professionals to gather important information from customers, ensuring that they fully understand what the customer is looking for. Additionally, listening is a vital skill that involves paying full attention to the customer’s responses and concerns, which helps in providing effective solutions and enhancing customer satisfaction.

In contrast, while expertise in mathematics and statistics can be valuable in certain contexts, it does not directly contribute to the interpersonal aspects critical in customer service sales. Similarly, technical knowledge of competitor products may be beneficial for competitive analysis but does not foster the customer relationships that drive effective sales. Advanced negotiation and conflict resolution skills might be important in complex sales situations, but they are secondary to the foundational relationship-building skills highlighted in the correct answer.