Purple countries indicate less than 50% of the population has access to the internet. Basically Africa, Central America, México, the Caribbean, and the Andean region of South America (plus Paraguay and the Guyanas), Asia (including of course India and China, but not South Korea) and the Middle East (with a few exceptions, like Saudi Arabia). So there is a belt around the middle with countries further South (the Southern Cone of South America, including Brazil and Australia) and further North (North America and Europe, including the East and Russia) that are fine. Understanding internet access provides an alternative way to look at development.
PS: The Wall Street Journal is really about Facebook trying to expand in places with low internet access.