<p>^^^
Usually, the company retains copyright. (Dante being employed and writing for hire.)The main thing keeping an essay mill from re-selling or publishing a paper is the desire to remain in business for the long haul. 
Reputations get around. It’s a “buyer beware” market, though. When [Duke</a> Prof Dan Ariely bought essays](<a href=“http://danariely.com/2010/09/15/new-school-year-plagiarism-and-essay-mills/]Duke”>http://danariely.com/2010/09/15/new-school-year-plagiarism-and-essay-mills/), he actually complained to one company because of the crappy quality. Ariely said the essay mill then threatened to contact the dean at Duke and report him for buying the paper.</p>