Facebook completes construction of first full-scale aircraft, Aquila [video] 11 years ago
I believe that as facebook gains the territory, so does Instagram, messenger, WhatsApp, and every other acquired product. So the plan isn't really to just deliver internet service but to buy up the social world in the area without competitors. Since about 1.49 billion of the 1/3 of the internet enabled regions use one of Facebook products even with the competitions, it's evident that this project would triple their impact.