First up, let me be clear that wireless technology is utter black magic to me. SpaceX's satellite internet service may or may not work in densely populated area

First up, let me be clear that wireless technology is utter black magic to me. SpaceX's satellite internet service may or may not work in densely populated areas, I have no idea. But what if their target market (at least for the beginning) were under-served rural areas? There are lots of villages and small towns in industrialised countries where the highest speed you can currently get is in the low single-digit MBit/s. Loads of people currently have no good internet access options but could afford SpaceX's service (based on what's publicly known about it, the estimates I've seen are that it will likely cost something between $50 and $100 per month). It would also be extremely interesting to businesses in such areas (Germany has quite a few of these, for example). I think there might just be enough potential customers in sparsely populated areas to make this a profitable service. They can also provide backhaul for cell phone services in such areas. Oh, and if they can get it working on ships (small sailing yachts, pleasure cruises, and commercial shipping could all profit from this) and airplanes, that might be another nice market to capture.