Recently I needed a few domestic tickets in Brazil and wanted to book Business or First Class, but wasn't able to. After a search I discovered that there are appearently no domestic flights in Brazil which have a Business or First Class cabin. This surprised me very much. The distances in Brazil are huge (long flights), there are a lot of rich people in Brazil who, I'm sure, would be willing to pay more for more comfort + there are a lot of connecting pax through GIG or GRU in C/F on international flights (thinking of TAM now + all TAM *A code shares) who would also expect the onward flight to be in a premium cabin (i.e. the main reason why KL still has a European premium cabin, eventhough distances are usually much shorter). Compare that to countries like Greece, Spain, Portugal, UK, South Africa, Thailand, Morocco, etc. where distances are far shorter, people are generally less well to do (not EU countries of course) and most domestic flights there do have a C-class.
So question: is there perhaps a law prohibiting a premium cabin on board? Or is it really the case nobody in Brazil would be willing to pay a bit more?