Yes, I suppose that is a very general statement now that I look at it. I suppose the traffickers have a knack for finding the vulnerable in poorer countries. I've heard stories where girls were promised jobs (e.g. nannies, maids) and were given MP and escort work instead, all the while having their passport/paperwork withheld until they work off their debt. I suppose this is just one method among many.
To be fair though I want to mention that not all Asians working the industry are poor or trafficked. Lots of foreign exchange students who only have student visas, but not work visas, do MP/SP work to supplement their income due to the imposed limited options. I'd say that the students talk about this among themselves, so it would more be a networking aspect as an entryway.