The economies of scale are so great the margins are almost certainly fat. Other than cellphones I can't think of any electronic devices where that many identic

The economies of scale are so great the margins are almost certainly fat. Other than cellphones I can't think of any electronic devices where that many identical units were being produced--millions and millions of indistinguishable boxes. About 20 years ago as a consultant in the EDA industry I got to tour of a set-top box manufacturing plant in Taiwan and it was fascinating. While the boxes were identical on the outside, on the inside they were doing everything possible to cut both component and manufacturing costs, including experimenting with paper based PCBs (apparently much cheaper than fiberglass?). I have to imagine they've only gotten better at cost optimization over time.