Why is the indium market considered more promising than the US market for example?
I think that this directly depends on the number of people who need education. It is necessary to begin with those countries in which people most of all need it. That is why the founders decided to start with India and China.
I also think that when choosing countries the developers took into account how many people from the general population fall into one university. In India, the population is very large, which causes a shortage of universities. Well, also consider the level of poverty - in the US rating is higher.
The infrastructure of the country plays a very important role in this process. Roads, the desire to learn, jobs are all part of the factors that affect the use of such an ecosystem to a greater extent.