I wasn't accusing anyone of being a salesman.
*I* was the salesman. But FWIW, and honest one.

In the store we used many of the products we sold,
so I knew which ones worked and which didn't.

In fact I spent much of my time dispelling the misleading
claims of advertisers, and discouraging the purchase of
products that didn't suit the customer's needs.

Thanks to advertising and other misinformation,
talking a customer out of purchasing a bad item
can be harder than selling it to them...

"Excelsior, you fathead!"
-Chris-