That's true; the vast legions of workers brought into the US under false pretenses, who then have their passports confiscated and are forced to work for several years in excruciating conditions just to "earn" their freedom, are there for other reasons entirely. I recommend reading this article series, "Diary of a Sex Slave":

http://articles.sfgate.com/2006-10-10/news/17314668_1_massag...

Also, slavery is an economic institution, and so the benefits flow not only to the slaveholder but also his customers, and they can be exported internationally to customers like you; the costs are borne by the slaves.