Introducing Profit Builder for your iPhone. This FREE APP will allow you and your staff to calculate gross margin per hour for every billable hour in seconds! Simply input your variable costs (taxes, workers comp, VMS fees, etc). Then input the pay and bill rates and presto! Profit (or loss) per hour. Staffing firms know that profits are earned when an employee works. The more hours the same employee works, the more that employee and the staffing company benefit. It is in the best interest of the staffing company that the employees succeed, and it sure helps when profit is one of the motivators.