Knowing your customer and being attuned to their needs and wants is one of the most important qualities of a good salesman. It directs conversation as well as how you carry yourself to best relate to them and to see if it is a good fit. Here is an example of how you relate to your customer well, although ethically it may not be correct because of being insincere.
Ethan David 
Aliyah Shelatz 
Caroline Marie Dawson
This is definitely true, in fact I have seen many instances where an attuned salesmen made a sale simply because he listened to and was interested in his customer. For example, my grandfather, who hardly ever buys anything over $20, recently bought a brand new truck because a particular Ford salesmen was willing to talk to him and get to know him over a few visits to the Ford car lot. The salesmen listened to what my grandfather wanted and got to know my him a little bit, and in turn came out with a big sale.