Orkut is a non-factor in Brazil currently and has been for years now.

Facebook and whatsapp is used by basically everyone who has internet access [1][2]

Edit: Of course number of users does not imply in revenue, but the Facebook office in Brazil is also a gateway to other Latin American countries. So I would argue that the country might not be as unimportant as you seem to imply.

[1]http://www.statista.com/statistics/268136/top-15-countries-b...

[2]http://www.telegraph.co.uk/technology/2016/05/03/whatsapp-sh...