Speaking to the Wall Street Journal, a Google spokesperson suggested the company's efforts were altruistic. "Internet connectivity significantly improves people's lives. Yet two thirds of the world have no access at all." But there's also a financial reason to offer these two thirds a reliable way to get online. If at least one of the methods — balloon, drone, or satellite — can successfully offer high-speed internet to underserved parts of the world, then Google will also be in a position to offer its products and services to vast new markets.
Sounds like a very Googly thing to do. I mean that in a good way.