Whatsapp isn't really Facebook and it is ubiquitious. I live in Europe and have lived in Africa, I only know of one person that doesn't have it and they're tinfoil hat level paranoid (following a privacy scare earlier this year).
Whatsapp really is Facebook. Facebook owns them, lock stock and barrel, so I'm not sure what you think the distinction is.
I understand it's ubiquitous, but I don't personally use it, and can't imagine joining it. Nobody I know uses it, but I will absolutely allow as how that probably has to do with demographics -- my network of friends, family, and coworkers is overwhelmingly on iOS.
