"Femme Fatale" first single "Hold it against me" has been officialy certified
Gold in Mexico on May 08 of 2012, for sales of 30K in the latin country.
Spears' has a bunch of certified material in Mexico, with all of her albums (even "The singles collection") being officialy certified by Amprofon, she is one of the most succesfull international anglo artists in Mexico and probably the best selling anglo artist of the last decade in that country.
http://www.amprofon.com.mx/certifica...o=certificados
(Don't freak out, amprofon has just errased all the database and is only showing certifications received in 2012, for every artist).