How will Facebook monetize Whatsapp?

Whatsapp is one of the biggest acquisition by Facebook. Is the $19 billion dollar justified?
It has been over an year now and whatsapp is growing its user base at an exponential rate. Official records peg whatsapp MAP (Monthly Active Users) at 900 million. And still there are no signs of monetization.

So what is Facebook thinking and what are its plans of monetizing whatsapp?
Mark Zuckerburg is thinking big with whatsapp and focusing on a larger user base which is more engaged. Whatsapp has a different business model and an FB like ad strategy might not work for whatsapp.
Thus, some of the options which whatsapp can use to monetize itself are:

1) Whatsapp can be used for P2P payments. This is a huge use case for whatsapp but there are compliance issues and privacy risks which need to be mitigated before this option can be rolled out.

2) The other option which is much more promising is to leverage the power of connections and create a transactional model of connecting users to businesses. A number of such companies have sprung up in India and are trying to implement this model, some of the names being Haptik, Helpchat, Lookup, Goodbox, LazyLad etc. The model looks really promising and seems like the next big thing in e-commerce world.

Even in the words of Zuckerberg:
"The long-term bet is that by enabling people to have good organic interactions with businesses, that will end up being a massive multiplier on the value of the monetization down the road, when we really work on that, and really focus on that in a bigger way."

WhatsApp already allows businesses to set up accounts that they can use to send content or marketing messages to people who connect with them.
Wishing luck to Whatsapp and all these budding startups trying to create an ecosystem which connects us to multiple businesses at ease!