In Brazil PS sells more than Xbox still I only ever seem ad for Xbox (not that many) but never for PS or Nintendo. Anecdotal evidence doesn't prove anything.
I guess this means that MS really tries and cares about Brazilian market. Not surprising actually, they are doing pretty well there as far as I know.
Yep I would say that both companies have interest in our market (some places say we are like 5th or 6th biggest console market).
I have seem MS putting ads for Xbox several times and for PS I see Sony putting their exclusives for R$200 vs 3rd parties R$250 and Nintendo R$300, and they have kept the same price when USD to R$ ratio gone from 3:1 to 4:1.
During X360 days they sold probably much more than PS3 with the strength of Live for "richer" customers and the modding/piracy for the "poor" customers. PS3 took a very long time to gain traction here. But this gen seems like PS have been a little stronger than Xbox over here.