If WhatsApp were a country, it would be the third biggest after China and India.
Co-founder and CEO Jan Koum announced Tuesday on Facebook that the Mountain View-based instant messaging service he established in 2009 now has 700 million monthly active users worldwide.
WhatsApp hit the half-million user mark back in April, a few months after Facebook bought it for about $21 billion. It hit 600 million users in August.
Above: The WhatsApp headquarters is located in the Speck building in Mountain View, Calif., on Thursday, Feb. 20, 2014. (LiPo Ching/Bay Area News Group)
