Lets say my service cost for color is 06 per page and I sell for .05 per page. The contract includes 10K color per year for 5 years. That totals to 50,000 color pages and the amount is $500.00.
That $500 is taken away from the total revenue and given to service to make it whole. Thus if the revenue of the sale was 7,000 it now becomes $6,500