IMO, if I convince you that you need to spend money on something you don't need, and most of that money ends up in my pocket, I am a scammer.
Didn't you just give the job description for the occupation of "salesperson?"
I hope that was meant as humor rather than a fact?
Why, why as a personal consumer...I love professional full-time salespeople! I can't even begin to talk about the products that until I encountered the salesperson that I learned how much I needed the product, a product that I often hadn't even heard about before the salesperson told me about it. Thanks to their sales info I found out I desperately needed the product. The product would "change my life" and for the better big time. It would add years to my life and and improve the quality of it too! I would also look better feel better and be more successful in life. And the preceding just scratches the surface. It doesn't even begin to cover the spectrum of their contributions along the lines I mention. Plus most, not all had great credentials and appeared if not in person on reputable large successful commercial TV and radio stations.
Oh, sure there are some that are not so reputable but no occupation is perfect.