Every Adwords guru wannabe knows that you have to have at lease two separate campaigns with same settings except for geographical location - one for developed world and one for 3rd world countries.
Why's that? Because each keyword you use costs differently in different countries. For example, if USA is selected, one keyword costs $5, and without USA selected, but for example India, Africa, South America, ... you can get same keyword for as much as $0.2.
So, to make proper campaign split between world of costly ads and word of costless ads, one have to make A Good Country List - the one that divides those two word properly.
Of course, I can make 10 campaigns, and divide whole world between them, then monitor that is First Page CPC requirement for each keyword I'm interested there, then shuffle with the country list, then monitor again, but that seems like a pretty lots of work.
Any idea of how to make such division easier?
The division is going to be more complicated than you think, not less. At best you think you can divide your campaign into three groups, US, other industrialized countries, and third world countries- but actually it doesn't work that way.
Are your ads all going to be in English? If they are all in English, do you think the same wording will work as well in India as it does in England? Subtle changes in wording in ads for a US audience make a huge difference. The same is true in other countries. Simply changing between the words "trial" and "demo" in our ads made a 1.4% different in click through rates.
In addition, most of the world does not speak or read American English. America has its own English dictionary. We spell words differently. Spell something in an American fashion in another country and they, at best, think you are an arrogant American. At worst they think you can't spell!
Gary E. Makes a great point. In the US you say "custom apps" in the UK you'd use "bespoke apps". And if you go to France, Italy, Spain or even Germany, they tend to look at stuff in their local language.
Another important aspect is that the world is not divided in US and Rest of the World (unlike some people like to believe).
If you target Europe, for example, you should consider sub-regions and create a campaign for Benelux, one for Northern Europe, one for the UK, one for Southern Europe (like Spain, Portugal, Italy and Greece)...
Another great split you can do is between the Search and Content network. For example, I have keywords that cost 20€ in the Search network, but cost less than 1€ in the content network!!! What I do (with great results) is to take those keywords that are too expensive to bid on, and move them to a Content Network campaign. There I run the same ads (in terms of ad text) but the keyword bids are completely different (and grammatically cheaper!).
Hope this helps.