Living on the Oregon Coast I don't normally see a snow plow unless I drive over the mountain passes. They are usually attached to big ten-wheel dump trucks, but when I was growing up a lot of people with four wheel drive trucks or Jeeps had snow plows.
First of all there were few pick-up trucks in the suburbs of New Jersey. It was only the hearty, self-reliant, good-ol-boy types that owned them. The hard core had 4 wheel drive trucks and most of them had snow plows. These guys would always keep an eye to the sky hoping for a hint of snow. As soon as four inches hit the ground they brew up a thermos of coffee and hit the road.
They had their regular customers and they'd work all day and night plowing driveways all over town. I don't recall how much they charged, but I somehow recall the average driveway costing about $25. Some customers wanted the snow removed only if it was over a foot deep.
Plowing is hard on trucks, but I think a couple good winters could easily finance a new truck. If you were fortunately able to snag some big clients like a shopping center or any place with a big parking lot you were really in the gravy.
It seems like a job I'd love. If I ever move to a colder climate I'm going to get a snow plow.