Many may have already been users before the acquisition by Facebook. There were apparently over 400 million active users prior to the acquisition. https://web.

Many may have already been users before the acquisition by Facebook. There were apparently over 400 million active users prior to the acquisition. https://web.archive.org/web/20140412064444/http://blog.whatsapp.com/index.php/2013/12/400-million-stories/ https://web.archive.org/web/20140412064444/http://blog.whats...