I was really surprised to see how different results are - it can be as big as between 0,2% for one country and almost 2% for the others. It seems like there are two sources of these differences:
- internet adoption in the country - especially for countries early on the path to use Internet - Serbia, Bulgaria, Africa (all countries but South Africa), Ukraine and some others.
- cultural implications - more difficult to judge and measure - things like:
- attitude toward marketing and advertising. Some countries (e.g. eastern Europe ones - Hungary, Poland, Czech) don't trust advertising and therefore are not assuming that banners lead to relevant countries. This results in lower clickthrough
- how focused people are - some countries don't mind distractions and are more eager to choose different path by clicking banners (I've seen it in Turkey).
The differences of ClickThrough for same banners can be really astonishing. You see others factors? Don't agree with my remarks? commentsents welcome!