I’m guessing debt, as a reason, is mostly an East Asian thing. I know this site is called AMPreviews, but I mostly see Eastern European and Indian girls, and they’ve never said anything like that to me.
Some of the former USSR girls came here after finishing school, with the intention of settling here for life. The money helps pay for college. Some stay in this business after they graduate. Some come here periodically to make some money, then go back. The average salary in Russia is about $600 a month.