Once you reach a certain scale of users, percentage growth don't matter because it's hard to hit big absolute numbers. In whichever way you look at it, 52Mn is a freakishly huge number. And this timeline is 6 months, not a year.
Further "Free basics" has been launched in other countries. But there is not proof that it results in more internet connectivity. (http://www.business-standard.com/article/economy-policy/ther...)
