It seems more and more prevalent these days that a few TEFL providers are writing their own TEFL/TESOL reviews and even creating their own TEFL review sites. This doesn't happen a lot but there are some really terrifying examples of it going on with a Prague course right now. It should be a concern to you if you are researching courses and a sound way to pick the good courses from the bad.
If you feel uncertain about a school regarding course quality, job prospects, housing...etc there's an easy fool proof way to to check if it's legit.
My advice is this - reviews and testimonials are great, but if they are not backed up by Facebook profiles or a clear way for you to contact these reviewers/graduates, they may be fake. We have dozens and dozens of testimonials and positive reviews from students. However, they only mean something, because you can contact these people. If you can't contact them, what's the point?
I know it sounds crazy (and it is) to think that there might be a 40+ year old man pretending to be a 23 year old Californian girl, but it happens unfortunately. Keep your eye out for this kind of thing. In today's social media climate, there is absolutely no reason for a school to not be able to get you in contact with a dozen or so recent graduates of the course. There are good TEFL courses/schools out there and there a few really bad ones. Both want/need students to stay in business.
Positive TEFL reviews for courses are great way to get new applicants and if a school is sub par they will have to resort to writing fake reviews about their TEFL program to compete with good courses that don't need to. Believe me when I say that they do. Furthermore, there seems to be a course in Prague that has created their own review site (or works with a TEFL review site) to write positive reviews for themselves, block negative reviews about their course and potentially write negative reviews about other Prague TEFL courses.
But Don't Worry, just get real feedback.
Most legitimate courses have graduates that are happy to share their real experiences with you via email or Facebook, Twitter ...etc because they understand the apprehension and anxiety that comes with packing up your things and moving abroad. Real graduates of any course are happy to help and a quick email or Facebook chat isn't much to ask for.
If you encounter a course with tons of positive feedback, but no way to actually contact these people, there's probably something fishy going on. If a school can't or refuses to connect you with graduate contact for whatever reason, they probably should be avoided. Best case scenario is that it shows the school is not connected with their graduates post course, which they should be for job/housing/networking help. Worse case, is that those testimonials might not be from real graduates at all. Generally speaking, if a school is well liked, they will be represented on many different review websites and not just one in particular.