Those countries are getting wealthier and the economics of the world are slowly shifting. We have maybe 1-2B people online with capable devices and abundant bandwidth. That leaves 5B yet to connect and another 3B who will want to connect over the next 50 years as population continues to grow.

You can see Facebook and Google scrabbling over themselves to get a share of the emerging markets. Google is trying to pair down Search so they can get it onto those 2G connections. Facebook is trying to give away bandwidth. They both know there is going to be a lot of money in those markets soon, but no one knows exactly how that economy is going to evolve.