Most commercial flights operate in a small number of fairly narrow corridors. Is there really a billion dollar market for aerial imagery of those flight corridors? Seems unlikely.
I know of one market-maker HQ'd in Manhattan that currently pays $16 million/year for two satellite images per day of the oil storage tanks in Cushing, OK. Analysts determine tank volume by looking at the shadows cast by the floating lids on the tanks and use that data to set oil futures prices. There are roughly 1,500 flights over the same area every day. We're very much a hypothesis-become-startup at the moment but I'm optimistic!