This is only really a shot across the bow if Facebook ports their messenger app to feature phones.

WhatsApp and the like didn't invent mobile messaging, they just went through the trouble of building J2ME clients across all the cheap handsets found in the developing world so that mobile messaging was available across all devices. Facebook isn't going to make any dent at all in the developing market unless they do the same.

Do you know if doing J2ME apps is still necessary in the developing world?

Sorry, didn't see this. But yes, the vast majority of handsets are still dumb, lots of Techno J2ME handsets still being sold.

That said, Android is getting so cheap that it is turning into a chasm between totally dumb phones (not J2ME, just a simple handset) and Android. The former is still the vast vast majority.

... and LINE, and Kakaotalk, and ...

The thing is that many of these apps are both pretty good, and have insane market penetration... It's hard to see why anybody would switch to a FB app that's very likely worse if they're already using something else (so all their contacts are there).

If they're on Facebook all their contacts will be on Facebook Messenger. Does Facebook have poor market penetration in Asia?

I do not have numbers, but while a fair number of people use FB in Japan, it's far from the juggernaut it is in the U.S. According to Wikipedia, Japan has about 17 million FB users, Korea about 10 million, and China only about 0.6 million!

LINE, in the meantime, just celebrated its 300 millionth user, and its user base is concentrated in Asian countries.

Yeah, if Poke couldn't take down Snapchat, then I don't know what hope this has of displacing those other apps.

They didn't really throw much weight behind Poke. They also had the fb camera app which was a competitor to instagram if you recall. Poke I thought was a weekend project.

Yeah, developing nations like most of Europe and so on...

Most of my friends in South America use it, that's why I said developing nations. I do have EU friends who use it, but their coverage is typically better.

Affirming the consequent?

I wouldn't limit that to developing nations, pretty much everyone I know uses WhatsApp in the UK, simply because mobile coverage is so poor that it's easier to send a Whatsapp than it is to send an SMS.

I seriously hope it doesn't cause any issue for these companies, I've just got back from a few months travelling and Whatsapp was invaluable.