[jeltz]

I think this is very local. Here in Sweden I have only ever met one person who used Whatsapp. I feel most people use Facebook messenger with some use of Skype, Google Hangouts, Telegram, Signal and Slack.

[oblio]

In at least France, Romania, Luxembourg, Italy, Germany, WhatsApp is very popular.

By popular I mean "small businesses start advertising contacting them through WhatsApp"-popular.

It would be nice to have a breakdown of these numbers but we'll probably never get them from FB.