Both Overture and Google Adwords have quite good ROI if managed properly, however if you dont do your research ANY PPC can cost you a lot and make you a little. Its all about finding high converting words that dont cost more per acquition in traffic then your making from your net profit.
this is a very nice and easy earning source but i like to visit to that site which have the facilities of translation.pk Arabic Translation of these all detailed above mention topic.