Food bloggers dish up plates of spicy criticism (Yelp's far reaching influence)
sfgate.com
sfgate.com
I have a friend from Vietnam who started a restaurant in my hometown, which has a Vietnamese population of around 30-50,000. He told me, just before opening, that the first 3 days would make or break the shop. That's the way that community worked: hundreds of people would descend on a new restaurant and then go tell all their friends and relatives. So he put tons of effort into the first days. Sounds just like... Yelp!
Rules change, people adapt. The restaurants should read PG's essays on listening to early adopters.