"Our goal in creating WhatsApp was to empower people through technology and communication, no matter who they are, or where they live. 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. This isn't a count of people who just registered for WhatsApp - it's the number of people who are actively using the service every single month," WhatsApp's CEO, Jan Koum, via a blog post.

Though, WhatsApp has two major competitors Line and WeChat but the company is striving hard to expand its user base in tech savvy countries like India. A recent report also states that WeChat, a product of Tencent, had piled up to USD 200 million for overseas marketing.

In November 2013, the instant messaging app Line had crossed 300 million user base. An official statement by the company said that it crossed 100 million subscribers in mere four months time.