That's the difference for us. We don't sell a product, we sell a professional service (ie: our time and reports), I know what I get paid...I also know what I bill out at...that is a big difference, but that is how the company makes money and pays for the non-billable people. I get it.
When I was in public accounting, they billed my time at 3+ times my actual pay rate. That does cover nonbillable staff, IT, benefits, and all of the other administrative costs that go into running a service business.