I think the original idea was to vote on how we as clients found the reviews "usefulness" to us but in order for us to vote accurately we could not vote until we returned from seeing that escort. JamesCork mentioned this previously....
I have to agree with him in that I don't see myself returning to a review to express my opinion on how helpful it was unless the review completely led me up the garden path and my appointment turned out to be a massive disappointment.