Here's a Funny or Die Yelp sketch that rings pretty true. Two Yelpers walk into a restaurant and suddenly everything is fodder for a review: A sticky door, a "weird" fork, a waiter who calls the Yelpers "ladies." Also, they judge a fellow Yelper based on the fact that she "gave Olive Garden three stars because they gave her too many breadsticks." Duh, doesn't everyone know those things are endless?
Video: Tricia & Johanna: Yelpers