Atkinson, William Walker: The Psychology of Salesmanship. V1. 21-Jul-2013
 

William Walker Atkinson (December 5, 1862 – November 22, 1932) was an attorney, merchant, publisher, and author, as well as an occultist and an American pioneer of the New Thought movement. He is also known to have been the author of the pseudonymous works attributed to Theron Q. Dumont and Yogi Ramacharaka.

Until the last few years the mere mention of the word "psychology" in connection with business was apt to be greeted with a shrug of the shoulders, a significant raising of the eyebrows--and a change of the subject. [...]
But a change has come to the man in business. [...] In fact, if he has thought sufficiently on the subject, he will have seen that the entire process of selling goods, personally, or by means of advertising or display, is essentially a mental process depending upon the state of mind induced in the purchaser, and that these states of mind are induced solely by reason of certain established principles of psychology. Whether the salesman, or advertiser, realizes this or not, he is employing psychological principles in attracting the attention, arousing the interest, creating the desire, and moving the will of the purchaser of his goods.