They lost something close to $138MM the year before Facebook purchased them.

https://mobile.nytimes.com/blogs/dealbook/2014/10/28/faceboo...

I'm a philistine, can someone explain how they paid their engineers when they lost SO much money?

They didn't lose SO MUCH MONEY, that's the thing. The article link points that out. They "lost" money on paper by handing out stock/equity to attract talent. Their actual financials, while underwhelming, looked solid.

WhatsApp was a very lean shop (and, btw, mostly (all?) FreeBSD). At acquisition, IIRC, they had about 40 employees total (or maybe it was 40 engineers).

I think if I remember correctly one of their main cost was paying a service like twilio (or something like that) to verify phone numbers of users when they registered to use whatsapp. Anybody has an idea if they are still outsourcing that verification part to a third party or doing in-house at Facebook?

There's not option to pay for anything, so I couldn't pay even if I wanted to. IIRC, the registration screen even said it's be free forever.

Given that they have extremely little metadata too, I actually wonder if they have any revenue stream.

They didn't burn through lots of money at all based on facebook financials. And they charge $1/month for the app (although I don't think on all platforms). I don't recall if it was + or -, but their "profitability" was less than $10 million in either direction so they weren't making or losing a ton.

I've used WhatsApp for years and have never been charged a dime.

I'm not sure what to tell you, I'm not fabricating the fact there was very much a yearly subscription fee associated with the app (and prior to that a price to just download the app). I'm aware it didn't apply universally which is why I specifically said it varied depending on platform.

https://www.imore.com/whatsapp-moves-yearly-subscription-pay...

Well, you claimed in the post I responded to a monthly subscription, not an annual one. What's a factor of twelve between friends?

My understanding is that the annual fee was essentially nonexistent, honored far more on the breach than in the observance, though all I know for sure is that they never charged me.

Or one might have not even noticed it. Just a click somewhere in a dialog, end of story. Among 10,000 other events we go through everyday...

Not sure why I typed /month, it was always a yearly fee or a flat fee to buy the app. Can't edit it at this point.

I have an iTunes receipt from 2013 for 69p paid for a year's worth of Whatsapp service. Their message then was "we charge because we don't want to show you ads".

IIRC they were always free in emerging markets like India though.

It varied by country. Some places it was $1 for the app. Other places, $1/year. Other places, free entirely. My guess is their goal was to make enough money to keep in the black, but to otherwise not worry too much about revenue. That let them maximize growth while avoiding the headaches and dilution of raising money.

it doesn't rule out the fact that there was an annual subscription fee at some point in time.

https://blog.whatsapp.com/615/Making-WhatsApp-free-and-more-...