It looks like whatsapp has begun profiting from Facebook's acquisition last February , The app just exceeded 500 million users, it's a record placing it at the top of the instant messaging applications.
The news was announced by whatsapp via it's blog where they pointed out that it has 500 million users active, in addition to that they announced that its users are sending 700 million pictures and 100 million videos a day, which means that the company made in just two months a remarkable progress and an increase of 50 million active users.