I worked as a freelance academic writer for about 5 years and Uvocorp was one of the 7-8 sites I worked with. I totally agree with Norbert. Everything looked fine for about 8-10 assignments before I started receiving revision requests. I had them review their comments and remove fines for the first two revision requests. However, I just gave up when I got the next seemingly senseless plagiarism remark. I was not sure if it was unintentional from their part, but I felt annoyed and disappointed by then.
These little jobs are done by people who log on to a company’s site and choose tasks, which could be as simple as clicking a link. Amazon's Mechanical Turk is one of the most well-known sites of this type. Also, there are crowdsourcing projects, which are similar to data entry, where companies engage an army of virtual workers to each do one small part of a larger project.