Only folks aren't always just paying $1. He's describing folks needing to set up a freaking payment system for a small amount of money - and that some folks aren't going to be able to do that and others aren't going to be willing. That's even before you get into the actual payment of $1. And this is before even considering there are other free apps that will work. There is a limit to the inconvenience folks will go through for your product if there are simpler alternatives, and being blind to this sort of thing could kill your company.
It also doesn't mean that folks cannot profit from ads. It isn't like all ads require you to pay through the internet - On my phone, I've gotten ads from a local coffee shop chain. I liken this sort of ad a cable tv ad. It might not get folks clicking on a website, but it might get folks in your store.
All this is besides the fact that we're talking about making the subscription model an option in addition to the ad-supported model, not forcing a subscription on everyone. I don't think a single person in this thread has suggested that apart from the people using is as a straw man.
These folks are very wary of subscriptions, regarding them as potential scams or traps and while I'm sure Whatsapp would be successful even with a recurring price tag, I'm confident the service would be nowhere near as ubiquitous as it currently is.
I would pay for whatsup through paypal or something like that.
However India is an extremely price conscious country, and many people would jump ship if WhatApp switches to subscription only. I tend to think that people would tolerate WhatsApp ads if they get the app free.
It will be interesting to see how this will play out.
I still think it's weird to have a product that worth so little to people that they won't pay a dollars a year, and yet it seems to essential in their everyday life.
Regardless, it won't get Facebook the billions they spend on WhatApps back.
Ads aren't magical things you can slap on a product to make it profitable. For ads to work you need an audience that technically could pay for you product, but who opts not to. You need to understand that Google isn't a create example of ads working, they are the exception. Facebook sort of works, but the US (and to a minor extend the EU) audience subsidies the rest of the user base.
Your right in that the $1, even at $1 per year, Facebook wouldn't be able to recoup the purchase price of WhatsApp. They won't be able to anyway, WhatsApp was never worth $19B. Facebook vastly overpay for the company. The WhatsApp purchase should be seen solely as a way of removing a company that "stole" screen time from Facebook, and now they're looking for an excuse to shut it down and roll the users into Facebook Messenger.