Marketing for a job shop, where you basically will take any work that will fit on your machines, is one thing.
And its something I know nothing about- because ever since I started working, way back in the early 70's, I realized that it was pretty pointless to try to race to the bottom against everybody out there.
So, like many people on this site, I have gone after certain markets, niches that I know something about, and therefore can easily talk about why I would be a better choice to hire.
It seems like in this day and age, with China doing everything for less than my cost of materials, more and more people are specialising-
I know on this site, we have people who specialise in paintguns, vintage auto engines, steering wheels for english sports cars, racing fuel injection, boat propellers, bike building tools, european racing motorcylces, harley engine rebuilding, micro minature EDM, precision machining workholding tools, printing presses, aerospace electronics, RC Model airplane parts, model train parts, all sorts of specialised firearms parts, obsolete tractor parts, swiveling vises, minature roller skates, high end woodworking planes, knives, and on and on.
None of these people would particularly benefit from a normal sales rep- usually they know much more about their respective markets than any rep would, and just trying to explain to a rep the ins and outs of their product and marketplace is more work than just selling the stuff themselves.
The old idea of a sales rep goes along with the old, pre 1980 version of the american wholesale/retail/distributor marketing system- which, in most industries, is long gone.
In the old days, a sales rep would get a guaranteed geographic area, and be responsible for writing every order in that area.
That is all shot to hell these days- the big accounts want direct factory pricing, with them dictating product design, price points, packaging, and so on.
The small accounts want internet ordering, and play off different manufacturers or even distributors against each other for product, price, and delivery times.
And for custom work- heck, the last thing I enjoy doing is talking to an independant sales rep. I want to talk to a guy who knows exactly the machine capacities, shop experience, material on hand, and all the other little details of the shop. I dont want to hear "I'll have to check on that and get back to you".