What’s the official language of the United States? It’s a trick question… there isn't an official one. Data from the 2015 US Census puts English in first place with Spanish second (up 200% to over 37 million native speakers since the last census). So even for the home US market, you’ll have linguistic considerations.
There are over 3 billion people online (40% of the world population, up from 1% in 1995). And it’s no surprise that the growth is coming from developing economies. This list shows the top ten countries currently online (screenshot from http://www.internetlivestats.com/internet-users/).