[ksec]

At the moment Zero. WhatsApp on its own doesn't make any money at all. Apart from some meta data about you and your contact.

But WhatsApp on itself doesn't cost much to run. They had 1B user and was running it on 50 Big FreeBSD Box. With a tiny engineering team. And that was with Hardware and Software from 6 - 7 years ago. Modern Hardware with all the BEAM VM improvement would made it even lower. ( Kind of Amazing if you think about it )

[avinassh]

Do you have any source for this? And more information about their infra costs?

[ksec]

I cant find anything at the moment. But it was quite well known. Big Box Hosted on Softlayer, FreeBSD and Erlang.

They had to switch to Linux once they were acquired by Facebook to keep a common platform.