You load a document into Coverage before printing. Coverage analyzes the document and provides a detailed ink usage statistics for every page of the document.
You see the total cost of printing and check if everything is OK there. If it is not, you check the document page by page to find the most expensive ones. You then modify these pages or charge an extra fee to make sure you are in profit.
You save the document details to the database for further analyzis and print the document for the customer.
All done, you've just saved a few dollars that will make thousands by the end of the year!