The 10/40 window term is used by Christian missionaries to loosely define areas of the world with the "highest level of socioeconomic challenges and least access to the Christian message and Christian resources on the planet" (Source: Wikipedia entry "10/40 window").
However, is the 10/40 window term sort of quaint and grossly oversimplified?
The reason for asking the said question is because apart from the glaring error of the 10/40 window not including the nation with the highest population of Muslims which is Indonesia, it also does not include very poor Central American and some South American nations.
Furthermore, the computer internet technology advancements that started around 1995 have led to smartphones and rapid growth of the internet so a lot of poor nations even have access to the internet.
Finally, it really seems like is it a gross oversimplification because a lot of European nations that are culturally Christian like France, Sweden, Germany, Norway, Denmark, Eastern European nations, etc. have a lot of nominal Christians and atheists but said nations are not in the 10/40 window.