This sentence could be understood as: - First-class salesmen are good at showing their own characteristics and advantages to potential customers so that they have trust and interest in their products or services; - Second-rate salespeople relied more on promoting the product or service itself to attract customers by emphasizing its uniqueness and advantages. - Third-rate salespeople focused more on how to promote products or services to existing customers and ignored the interests and needs of potential customers. This sentence reminded us to pay more attention to self-marketing and customer demand mining in the promotion process to better achieve the promotion effect. At the same time, they also needed to constantly improve their marketing skills and abilities to better adapt to the changes in the market and customer needs.