In the mobile messaging battle which we can say WhatsApp is leading, WhatsApp has further given data supporting its leadership in mobile messaging. WhatsApp has revealed that it now has over 400 million active users per month. “ WhatsApp has reached a milestone that no other mobile messaging service has achieved: 400 million monthly active users, with 100 million active users added in the last four months alone. ” WhatsApp’s CEO, Jan Koum revealed in a blog post.