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.
Here in Mexico, any mobile data package comes with free data for blessed services like Whatsapp and FB Messenger. Obviously trying to compete with each other on these perks.
Using a competitor like Telegram is a complete nonstarter when trading memes or video chat eats into your data. The cheapest plan from Telcel (pay-as-you-go + holding 20 pesos in your balance) lets you use Whatsapp infinitely.
GG to competition.
It is probably illegal (on the paper we have net neutrality, the telcos just blatantly break the law) to do so in Sweden which why some telcos are in a legal battle with our regulatory authority.
While useful to people, most of whom want to just go to Netflix, that level of integration doesn't feel right.