What is difficult selling or purchasing?or you detail your product to a doctor and he Rx product to a patent so what are real sales?

well, i can't really understand what is the exact meaning.

but coming from both backgrounds ,being a certified professional  purchase manager and a sales manager for many years, i would really tell you each job has its challenges.

you can't really compare two  fields who are somehow interrelated.

in my company procurement and sales where interconnected and depended on each orher.