The reason a salesman can make a lot of money is very simple: no matter how efficiently a business is run, it will go under without revenue to pay the bills. Investors pay the bills when a business is starting out, but they want their money back in spades. In order to gain revenue, you must make sales.

There is a difference between thinking an item might be cool to have, and handing over your credit card. Or for a larger film, the purchase order. In a capitalist society for almost every product the new firm will face competition. Which means somebody else out there is making something similar, and maybe even better than your product or service. A good salesman can be the difference between your firm getting the order and one of your competitors.

In other words, salemen make the big bucks, because they bring in the bucks. In wholesale, that is. Unfortunately, in retail the salesman don't often make that much. My stepfather used to manage the Nautica department of a nationally known department store chain that shall remain nameless. Even with Nautica supplementing his income, and his commission, his earnings were in the $20K range. Which is half what I earn in a good year working construction. The presumption is that the store and its advertising matter more than the salesmen.