How many of those users were actually paying at the time? IIRC they allowed 1 year of free use (even more depending on your country). I don't know what the churn is going to be the moment a currently free customer becomes paying, but it is definitely non-zero. I really don't think that is evidence for a long term sustainable business model if others exist with zero total subscription fees.
> I’m not saying that the ads model doesn’t have its place, far from it, I’m saying that WhatsApp could have lived just fine without it.
The biggest reason for WhatsApp's success was the cost of SMS messaging most international markets. That's actually declined significantly since its introduction, so that's another drag on their pricing power.
Could they have lived? Maybe. But I doubt they'd have 1.5 billion users like they do now, and I don't think they long term trajectory for the business would look sustainable charging $1 a year.
There’s a huge difference in the number of people willing to pay for an app “that I can connect to everyone with” and those willing to pay for an app “that I can connect to only the other people willing to pay $1 for”.
I initially ignored it then switched to it after they started to do end to end encryption and encouraged all my friends to use it, instead of Facebook’s Messenger.
So yes, they were already popular because the app was working on all platforms, because it is easy to connect with your friends and because it did what it was supposed to do without the crap.
I’m not saying that the ads model doesn’t have its place, far from it, I’m saying that WhatsApp could have lived just fine without it.