Here’s a mildly interesting story from Vietnam that illustrates why that market is so critical to test makers. As I’ve mentioned in the past, tests like the IELTS are used for admission to domestic universities – so volumes are high.
A testing company that can take a test designed for one purpose (study abroad) and figure out how to repurpose it for something wholly different (study at home) can make a lot of money. Especially if they can pull it off in a country with a growing economy and a fairly large population.
This sort of thing isn’t without controversy, though, as it does represent an enormous amount of currency being piped from the global south to firms based in the UK, Australia and the USA in exchange for a service that could probably be handled by domestic firms (eventually). I think the companies involved know that the good times won’t last forever.
Fun fact: In past years TOEFL scores were similarly important for Korean students applying to domestic universities. That’s why, when the TOEFL iBT launched in 2006, Korea had more TOEFL test takers than any other country. As late as 2015, I taught TOEFL prep to Korean children as young as twelve years old. But things have changed and TOEFL scores matter much less than they used to.