Almost everything they're done is centered around ads and getting more data on their users to sell more ads. Even this project, in the end it's about getting more people online to look at their ads. (not sure how much ad revenue you can get from poor places, but whatever)
EDIT: To those saying they're playing the long game; Playing the long game doesn't make sense. The long game is being fully wired. By the time poor areas become economically important enough to be advertised to, they will have traditional telecoms servicing them.
EDIT: To those saying they're playing the long game; Playing the long game doesn't make sense. The long game is being fully wired. By the time poor areas become economically important enough to be advertised to, they will have traditional telecoms servicing them.