Casey explains the concept much more eloquently than I can. You can watch her presentation to Google employees in the video below:
For more information see their about page, and be sure to check out their blog. Apparently some feel that China is a poor target, since it is now the third richest country in the world. Of course, that is an aggregate number that reflects China's large population. In per capita terms China remains very poor. We should be wary of income statistics for a fast growing and industrializing country like China because so many people (our entire pop.) are not involved in those gains at all. The rural area, which Wokai is targeting, is very poor. James Fallows had a good piece in The Atlantic last September that did a great job of telling rural China's tale:
But in the villages, people effectively live in a different century. Their families may exist on the cash equivalent of $10 or $15 per month. Their entire life experience may be encompassed within a radius of 10 or 20 miles. When my wife and I visited a high school in an ethnic Tibetan village in Gansu province, we were the first foreigners the students—or any of their teachers, or the principal—had ever seen outside of textbooks. At that school and others in the west, we talked with children who went to school in some years and didn’t in others, depending on whether their families had sold enough crops to pay the public-school fees. This is not the China that most foreigners read about or experience on visits, but its isolation and poverty are important parts of any understanding of China.Fallows goes on to discuss how two entrepreneurs went to pains to ease some of the hurdles rural villagers face, and the whole article makes for a fascinating read.