Is it the amount made from the sale of something?
Money made from exports per capita?
A divisor of 1,300,000,000.
Because of the fact that there is only one color, I think it has something to do with whether a country has or does not have something. Here are my observations:
All the large countries are red. All of the populated countries are red and all of the wealthy countries + a few large or populated countries are red. Most of the middle east is grey except Israel, Jordan, and Lebanon and none of South Eastern Europe is red. Uzebekistan does not seem to fit the pattern of wealthy, large, and populated countries having this. Neither does Ghana or Cote d'Ivoire. This leads me to believe that it could have something to do with geography but I doubt it. I'd guess it has something to do with a law adopted in these countries. That would explain why none of muslim countries are red.
DR Congo is definitely not a wealthy country.
From the looks of it I have to ask if it is whether a country has a certain resource in its borders? Amount of resource?
Again, this is something where the Netherlands Antilles, French Guiana and Channel Isles/Isle of Man and their respective mainlands are distinct in some capacity.
The United States accounts for nearly 90% of the total number.
So if a country is grey does that mean it has less than 1% of something or just 0%?
Is it a store's locations. Like a map of countries with walmart or taco bell?
Many of these countries, like Uzbekistan, have only 1 of the something.
People that like the United States.