That depends on the contractor. I've waited months in the past to be paid by one I had worked for.
Another advantage is the General Contractor usually carries the major insurance policy, reducing your operating expenses. Plus, if you are green to snowplowing, it's good experience to learn how to plow along side of others who have been at it a while.
If you can put up with the headaches and hassles of running your own business, you stand to make a bit more money if you're a contractor yourself.