Windows Phone is in second place in Latin America now. I wouldn't say "no customers" so quick.
In fact, were they clever, MS would position themselves well in all of the non-1st-world markets (Indian sub-continent, Central America, South America, Africa, Asia). Its like playing Risk, they've got America, Europe, and Australia, but you can still hold on with the others.
That would offer more scope for growth.
e.g. http://allthingsd.com/20130903/microsoft-deal-could-mean-end...
"But when it comes to smartphones, Microsoft only has the right to use the Nokia name on Windows Phones that are in the market when the deal closes"