I don't have seasonal contracts.
Some businesses charge a rate 1-3, 4-6, and on and lowers each time you plow as it becomes more. I have found that the customer is never happy then. You let it pile upbto 12 inches and then charged me X amount. They feel cheated.
Mine is on a billed as per push or per salt. This way they only pay for the service they want and get.
Old folks homes, u-hauls, those kind of places have me do it more often. Uhaul has massive storage lot facilities here....easy money.