I wonder how much of total SE searches are made in another language then English... like german+french+italian+etc.. What would be the ratio of English vs all other Non-english. And further more.. how can a non-english site make some decent money (except google adsense)... You think sending italians or spanish to some english written affiliate site can work? Are non-english visitors as good buyers as US or UK visitors ?!
Most SE support different languages. English ads make the most money, because about the entire world can read them. Local ads are only worth it if you have a local website.