salesmanship (n.)

1853, from salesman + -ship.
The modern system of salesmanship has become so much like persecution reduced to a science, that it is quite a luxury to be allowed the use of your own discretion, without being dragooned, by a shopkeeper's deputy, into looking at what you do not care to see, or buying what you would not have. A man in his sane mind, with the usual organs of speech, has a right to be treated as if he knows what he wants, and is able to ask for it. ["The Literary World," Feb. 26, 1853]