Watching people will tell you a lot about their beliefs, desires, values and behaviors. Each person comes with all types of needs. In sales it is vitally important to try and read what the customer is not telling you and make suggestions that lead to a higher level of sales. Moving beyond the conversation to the core needs of the customer can make all the difference in satisfaction.
A salesperson's ability to “read” people impacts sales volume and service quality (Puccinelli, et. al. 2013). With the right interactions the customer will feel that his/her needs were met through positive interactions. It also impacts the ability to solicit enough information to give the customer the right product.
Consider a customer who walks into a store and wants to buy something. Sometimes it is an urge to make a purchase that helps them look good, feel special, or whisk away a feeling. At other times they may need an actual product but are not aware of the options or whether or not there are alternatives.
An attentive salesperson can see the anticipation, ask the right questions and then lead the person to the product/service that best suits their needs. They do this through watching closely what is actually being said through words and non-verbal actions. If they pay attention long enough and gain experience they can get good at this.
Puccinelli, N. et. al. (2013). The value of knowing what customers really want: The impact of salesperson ability to read non-verbal cues of affect on service quality. Journal of Marketing Management, 29 (3/4)