At the university, you can study engineering, medicines, sciences, business, marketing, ... But can you study Sales? Why?

The university majors are just foundation to what facing at real work; sales is an example. But the best question, what the sales person needs to know before success at sales job, is he/she needs technical knowldge or just business knowledge is enough. My opinion is that he/she needs to know technically somehow to be able selling, but not advance techical knowledge.