For example, you set your advertising locations of one campaign for both USA and UK, the market your dealing with is much more competitive in the USA. When someone searches for one of the keywords in your campaign in the USA, your ad could be positioned at #9, but when they search for it in the UK, it could be positioned at #1.
This could average out in your campaign reporting as position #6. So is it best to setup a different campaign for each location so you can get a much better idea of positioning of your ads?
Hope that makes sense
My philosophy is to drill down the campaigns as fine as possible. Per-country seperation is a must, from my point of view.
Since you mention US & UK: there are a lot of differencies in spellings. So in the UK you would use the word "colour", and the US you'd use "color". A UK user would be much more inclined to cick on ads with the right spelling.
