India is inching closer to overtake the U.S. as Facebook’s biggest market, at least in terms of the number of active users. With over 100 million users as of March 31, India is now the only country where Facebook can aspire to have 1 billion users, thanks to a growing base of Internet users (currently around 200 million) and increasing proportion of mobile phone subscribers in its over 1.23 billion population. In an interview with India’s Economic Times newspaper, Javier Olivan, vice-president, growth & analytics at Facebook said getting 1 billion users in the country will be altogether a different challenge. As we have been writing, while India was expected to become Facebook’s biggest market in terms of number of users later this year, but it’s always going be difficult to translate that into ad dollars for the Palo Alto company anytime soon.