They didn't chose it based on privacy. But they have an expectation of privacy. The post office doesn't read your letters, so why would you expect Facebook to read your messages?
It's difficult to understand for the average person just how much Facebook knows about you and what it can do with that information that isn't in your direct interest. At best they think it's weird how long-lost acquaintances show up as suggested connections, at worst they only notice when Facebook does something directly useful to them.
Sure, you can blame the users, but that's kind of unfair if you consider what kinds of markets WhatsApp already dominated before the acquisition.
Well I do and I switched after they announced e2e encryption, otherwise I never would have used it.
Why does every thread on Hacker News have to ask this freaking question? It’s obvious that the general public is computer illiterate, Sherlock, just like it is obvious everybody knows someone “good with computers” that can tell them what to use and having lived the sunset if Yahoo Messenger in my country, Facebook should be scared as it happened practically overnight.
A LOT. Even in developing countries people paid ₹50 (or the equivalent of a $1). WhatsApp changes this model a bit by partnering with carriers. Unfortunately my memory is not clear on whether that was before or after the acquisition.
Edit: Note: WhatsApp publicly claimed that a billion users paying $1 each is enough for them. Also remember, a lot of the technical complexity, infrastructure requirement and data storage requirements went away in their model of being just a conduit. They had no interest in reading, parsing, mining, storing or monetizing the messages. This let them run it with a lean crew.
That was technically their business model, but they gave you one year free and also extended your 'subscription' indefinitely if you decided not to pay after that - basically the WinRAR of messaging apps.
On iOS the app used to be $0.99 (one-off), which probably made them a couple millions. In 2013 they moved to a subscription model [1] but this was never implemented; I think nobody was ever charged.
I paid for it too. I like to think that "idiots" like us prove that there is demand for a paid ad-and-tracking-free messaging service, so maybe our efforts weren't in vain.
I believe most users simply use it because it is the most used messaging app in their country