I would say the statement that they are making "good" money off your 35 a week is far from the truth. By the time they pay for broken units messed up wires, tech costs and all else I doubt if it amounts to much at all.
Depends on several things, like how large the fleet is and how long the QC units have been paid for. A small carrier with new QC units, the weekly QC fees are probably not much of a revenue stream at all, since the monthly usage fees on a per-unit average paid to Qualcomm are higher for smaller carriers, and the units are still being paid for, plus a maintenance "bank" needs a couple or three years to be built up. It takes an average of 100 weeks to pay for the units themselves out of our weekly fees. But once the maintenance bank is fully funded and the units are paid-for, a large chunk of that $35 a week becomes pure profit. A Panther, for example, of the $140 monthly QC fees, less than $20 a month goes to Qualcomm for the service, and about $4 a month goes to keep the maintenance bank funded. The rest is a revenue stream. $4 seems like a small number for broken units and messed up wires, but when you've got like 900 units out there it adds up quickly, as most will never need much in the way or repairs or replacements during the first several years of use.
My QC unit was 8 years old when I turned it in, and it never had anything done to it. No repairs at all (until 3 months ago when the up/down arrow buttons finally gave out and they replaced the head unit (keyboard) at a cost of $280). It was more than paid for by the end of year 2 (before the Con-Way buyout, actually, so mine was paid for before they even got it), and the rest was more or less profit.