Interesting discussion. I have been watching it.
I have a couple of questions?
Are you, Robert, able to write a review on Yelp about Yelp? It would seem only fair that such reviews should be allowed there. However, I can say that on Amazon, you can review the performance of every marketplace seller and every product -- but you can not review amazon's performance as a seller. I called the company to complain and the person who receives complaint calls didn't know that you can't review amazon.
I'd think for a company like Yelp that they should have two (or more) categories of reviews. Those from consumers (which will probably be mostly glowing) and from biz owners (which will probably be mostly snarling).
Second, have you seen this WSJ article about a carpet cleaning biz owner, how a Yelp review case is in the Virginia Supreme Court and about SLAPP and Anti-SLAPP suits?
http://online.wsj.com/news/articles/SB10001424052702303847804579477633444768964