> I like to see how much revenue Facebook gets from those countries vs. the US and Western Europe.
That's not even the point, even if they're loosing money at the moment it's almost certainly worth it to capture those new users.
> All the money in the world can't keep something fashionable forever.
Facebook isn't fashionable or trendy, myspace et al took that angle which is why they're gone now, and also that's missing the point again.
Facebook is a social utility that a crapload of people can't live without. I have friends who I can't even contact without using facebook/messenger/whatsapp, and this is in a country where mobile data is cheap and SMS/phone calls are basically free. Go to a place where facebook-subsidised connections are the only option that people can actually afford and your only alternative is basically social suicide.
I don't think many people truly grasp the scale and pervasiveness of Facebook and how there just isn't anything that is even remotely close to competing.