
There are some reliable writing websites out there. The problem, is that the fraudsters tend to be more visible than the reliable ones because those companies have more money to burn in terms of advertising, SEO optimization, and social media profiles. That is why it is difficult to separate the bad sites from the good ones.
The bad ones also tend to run more "umbrella" companies in order to direct more business their way, which again, creates a problem when investigating the reliability of the companies. These people pay for positive reviews just so people will keep coming to their site. As they say, a sucker is born every minute and that is what they found their business upon. I know of a few writers who have made a career out of helping to promote these scam companies by writing their copy for them. That is why I learned that the more positive reviews a site has, the more it should be distrusted by the student.
They pay for their publicity, thus making themselves seem legitimate even though they are not. Hiring a company instead of a freelance writer comes with more possible problems. So, rather than hiring a company, I think it would be best to go direct instead, eliminate the questionable middle-man and the writing process should become simpler and more on the level for the student client.
We can discuss how to assess a writing company for reliability and expertise still the polar ice caps melt and we will never come to a unified conclusion as to how to detect such websites. Assessing these companies should be based more on an individual experience. Cookie cutter suggestions and experiences don't work because there are some companies that may not be on the "legitimate" side but can actually deliver the work as promised. Some students may have good working experiences with such companies. So these students can say that they had a good working experience with the company, which translates into the company being "reliable" at least for that student.
The only way to prove the reliability or non-reliability of a company is to simply work with them. Don't start with a large cost order. Keep it simple and make sure that the money you are paying is something you are willing to lose in case the deal goes south. I would say that starting off with personal opinion papers / essays, then moving on to simple 2-4 page research papers and advancing further from there will help a student determine the reliability of a website.