For lack of a better phrase, reviews are a double edged sword. I won't even consider seeing a provider unless she has several reviews. I don't think I am alone in this regards. I don't have nearly the opportunities in this hobby as I would like, so I'd like to have a good idea what I am getting into. TOFTT is not an option, as reviews hedge against a wasted opportunity. However, as SimplyGFE points out above, that may mean I miss someone who is new and without reviews. I'm willing to take that chance as there are far too many ladies who have tons of reviews. So for the provider (or agency), reviews are a critical marketing tool. Though, just like any review, they have to be taken as just a single decision making tool, not the only tool. A lot of time they are used to determine who NOT to see rather than who TO see.
The other side of this is the writing of the review. Myself, I probably write a review 50% of the time. I imagine the reason for lack of review writing here (as with Amazon, YELP, Trip Advisor) is I'm just a lazy ass fat fuck. In addition to that, of the reviews I have written, I have had some negative backlash from the provider. This happened a couple of times. The first time, I mentioned something that was negative physically. This provider is a top provider by all accounts a 9/10 type. I mentioned a physical flaw and was flamed by both phone calls, emails, texts, etc. Strangely, I had a fantastic time with the lady and had seen many times prior to this. So, my honesty in a review damn near spilled into private lives. Not cool. Added to this is the provider has my personal info (as they should, 100% as a screening method), but it does give her the ability to be a problem.
The second time I mentioned in a review that the provider prefers CBJ. Nearly all her reviews stated BBBJ. She told me she asks for reviews to put in BBBJ to get a higher score and she thought that if the hobbyist knew only CBJ, then many would look elsewhere. Hence, the failure of the reviewing system.
So, after my long winded BS, is that reviews are a necessary evil in this business. Though if the gov't gets its way, they will gone before too long anyways.