I think it depends on what you mean by 'success'. My advertising brings in affiliates mostly from India. However, I also have so many affiliates from Arab countries that have not even contacted me. I think it may either be a language or culture barrier.
I don't consider any ad campaign "successful" (no matter how many people it brings in) until I see how many of those affiliates become actively involved.
-- "QUALITY, not quantity, is what you need to succeed." --