"As one of the most credible threats to Facebook, WhatsApp’s numbers speak for themselves. The company has more than 450 million monthly active users on the platform, according to the company, with more than 70 percent of users returning to the app on a daily basis. It has doubled in size over the past year, and sees more than half a billion photos sent over the service on a daily basis. Additionally, more than 200 million voice messages are sent on the service daily, along with more than 100 million videos sent. The company is adding more than one million registered users on a daily basis.
The company said on December 31 users sent 18 billion messages and received 36 billion messages, a total three times larger than the year before."Facebook to Buy WhatsApp For $16+ Billion | Re/code