I have plowed snow off and on for the past, well, for a good many years, and learned a few things about it along the way....

The individual asking the question asked about pricing...per snow, per inch of snow, per square foot, and the answer to these choices is,well,  yes. You figure out a base snowfall (which might vary for each property manager) and when that much snow has fallen, you have an agreed  "go ahead". Some property managers will always want to "authorize" each snowfall. (This is much easier in the era of cell phones :)

Besides the depth of the snow, there is the size of the lot to consider (square foot) When I started in New Jersey many years ago, I figured (in my head) a hundred dollars an hour for the plowing, so if a lot took half an hour, I would charge $50.00.on the other hand, I wouldn't drop the blade for less than $35.00. This may be harder to do now than it was 25 years ago, because there are so many more 4 wheel drive trucks out and about with plows on the front of them, but you are going to clobber curbs during the night and get caught by manhole covers that aren't set right and you need to make enough to cover the wear and tear on your truck, plus the actual welding repairs that have to be done now and again (sometimes by getting the welder out of bed at 2:00 am).

There are several common ways to structure plowing agreements. If you are lucky enough to land a couple of commercial parking lots, the property managers will sometimes give you a "contract" based on an anticipated amount of snowfall, say, for XX dollars you plow the lot each time there is 3 inches or more of snow, for up to 5 snowfalls. If you are astute, you will have a clause that calls for additional payment if you have more than a 10 inch snowfall, and yet more if you have a 15 inch snowfall, and so on. You need to build in protection for yourself in the event of a major blizzard, to be sure you are not on the hook for trucking snow off site to another dumping area because the piles start taking up too many parking spaces.

If you are doing parking lots you probably need to invest in a sander as well, because many property managers want to keep their lots in good shape. Some property managers want absolutely no slip and fall risk, and will OK plowing a 2"-3" snowfall, with sanding afterward, others will want you to absolutely wait until the snow has stopped so you only plow once and they won't care if traffic in and out has compressed the snow into potential ice tracks. You can also sometimes make money by taking care of the sidewalks in a business complex, but you need to be able to transport a snowblower around, and you need a helper to run the snow blower while you plow the lot. You don't want to park your truck to and have it sit while you do the walks as the truck is not earning money when parked.

I used to have a mixture of retail parking lots, a couple of office building lots and a couple of apartment buildings that I took care of. The Dairy Mart wanted to be done by 5:30 a.m., but Wendy's didn't care as long they were cleared by 11:00 a.m. when they used to open. The office lots wanted to be done by 9 a.m. and the apartment owners usually wanted me to Wait until it absolutely stopped, but they usually wanted me to swing by and clean out the driveways to the street, where the town plows had dropped big piles of compacted snow.

I plowed like this for a few years when I was in my twenties and thought it was fun. I remember leaving my house at 5 a.m. on February 5th, 1978 and not getting home until Thursday morning, and that was my experience of the great Blizzard of 1978.

Businesses have a stake in cleared parking lots, as customers can't come to them and spend money if they can't park, so they are usually good about paying their bills and honoring contracts. Unless you are in an intensely snowy area of the country, though, most homeowners don't think about plowing until they can't get their car out, or it is too big a snowfall for them to shovel. Driving around a residential subdivision with a sharp eye peeled can be a good way to drum up business, or additional business if you have time after your regular clients.