The number one tool in sales is language and the communication derived from linguistic dialogue. Language consists of abstract symbolic meaning that cannot be sufficiently codified into predesignated definitions to reflect the human condition.
In fact, Western Psychology is based on physical concrete observable data based on statistical algorithms displaying mental functioning. That means, they cannot capture the mind of any one person but set up only a structure representing a Virtual MInd.
The more we become technical the further we drift from humanity and sales is a very human enterprise.