BOB GARFIELD: It’s a classic device in sitcoms and movies. The characters who run a restaurant or a hotel catch word that a famous critic is coming to review their business – in, for instance, Twin Peaks.

[CLIP, TWIN PEAKS]:

ACTRESS PLAYING DESK CLERK: Wentz travels incognito. Nobody can trace his identity.

RICHARD BEYMER AS BEN: A favorable Wentz review could be quite useful.

DESK CLERK: Well, he’s coming, well, he’s coming. He’s coming, he’s coming.

RICHARD BEYMER AS BEN: Keep an eye on registration.

[END CLIP]

BOB GARFIELD: Business owners no longer need to freak out guessing, because now every customer could write the review that defines the restaurant, for good or for bad – all of this made possible, of course, by an array of websites that crowd-source the reviewing process to ordinary people, chief among them, Yelp, a website that started in 2004 in San Francisco and since has spread to 24 cities, with more than five million reviews posted to the site. Those reviews praise and bash every last business, from restaurant to nail salon. Jeremy Stoppleman is Yelp co-founder and CEO, and he joins me now. Jeremy, welcome to the show.

JEREMY STOPPLEMAN: Thanks for having me.

BOB GARFIELD: Jeremy, where did the idea for Yelp come from?

JEREMY STOPPLEMAN: We realized that people typically found new businesses searching on the Internet, and there must be a better way than simply browsing advertisements. And so what popped into our heads was, you know, a really good way to find a local business is to ask around, to ask friends for recommendations. And what we tried to create was a place where you could tap into word of mouth online.

BOB GARFIELD: You know, we've all read about the wisdom of the crowds, but how do we know that those who go to a restaurant can give us anything worthwhile by way of opinion? Now, food critics have, you know, some sort of expertise, haven't they?

JEREMY STOPPLEMAN: Food critics have a very precise palate. What most people realize is sometimes they don't necessarily agree with that one perspective. What Yelp provides is the opinions of many. You can browse around, read all the different reviews that you want until you get your fill, and then when you find a reviewer that has a perspective that sounds interesting, you can actually click on that particular profile and learn more about that person.

BOB GARFIELD: Is there a secret to reading Yelp reviews so that you don't focus on one particular critic and somehow manage to embrace the commentary as a whole?

JEREMY STOPPLEMAN: Yeah. So when you go to a Yelp page, the first thing you'll notice is that average star rating. So right there you have a very broad sense of how that business is doing. You also have a number of graphs that you can take a look at. You could see very quickly how many total five star reviews, how many four star reviews, how many one star reviews, and that gives you an overall sense of the big picture. The next thing you'll see on most pages where we have enough reviews to do this, we actually use software to pull out review highlights, so things people are most often talking about. And it’s always positive. It focuses on, what do you want to check out? What are the best dishes? And then, as you move down the page, you'll find the user reviews.

BOB GARFIELD: You crunched the numbers and figured out that 35 percent of Yelpers gave four out of five stars for any given service. Thirty-two percent gave five out of five.

JEREMY STOPPLEMAN: If you add it all up, 85 percent of all reviews are neutral to positive.

BOB GARFIELD: Okay, but I'm running Luigi’s, and Bella Luna, the pizzeria, opens across the street, and I'm terrified that they're going to cut into my business. So I, Luigi, and everyone I know, goes onto Yelp to start badmouthing Bella Luna, driving their number of stars down five, four, three, two, to, you know, let's say a half a star. Do you have anything, any kind of algorithm that looks for patterns like that to try to root out Yelp fraud?

JEREMY STOPPLEMAN: Absolutely there are protections in place both from the software side – as you suggest, algorithms – as well as you have very obvious things from the consumer perspective. You can see a given individual’s other reviews and you could see the feedback and awards, essentially, that that person has garnered within the Yelp community. And so as a result, it’s very, very difficult to create a personality [LAUGHS] on Yelp that does not reflect a real person. And that, essentially, is our foundation. We're not an anonymous review site. Most of the contributors have very deep profiles and reputations on Yelp.

BOB GARFIELD: Do you ever delete comments that are just manifestly false? You know, I found a mouse in my soup. I found a finger in my soup. I found a raccoon in my soup. Is there any protection against restaurant slander?

JEREMY STOPPLEMAN: We're not necessarily in a position to determine what exactly happened, and we want to make sure that all individuals feel that they can share their experiences openly. Now, that said, if a business finds something that they feel is clearly outside of our terms of service or our review guidelines, such as you’re talking about an experience that you didn't have but maybe a friend did, we absolutely will take a look at that and potentially pull it down.

BOB GARFIELD: There are a number of San Francisco restaurateurs who just feel that they've been blindsided by Yelp and that they have no recourse. How do you calm them down?

JEREMY STOPPLEMAN: This is word of mouth. There are people talking and there’s going to be the good with the bad – mostly good – and if you think about yourself as you might take a look at a Yelp page, you’re not necessarily going to hone in on that one stray negative comment. You’re going to be reading the review highlights that we call out that show the best things, the specialties of that business, and then you’re going to make your decision. While there is going to be the occasional bad review, like there would be for any business, that can actually add credibility. And, in fact, The Economist just this last week was talking about on Amazon and Google Shopping they're finding that if there’s a little bit of negative feedback, that actually adds credibility to the whole picture, because who expects a restaurant to be 100 percent flawless day in and day out with every single possible aspect of the business?

BOB GARFIELD: Jeremy, thank you very much.

JEREMY STOPPLEMAN: My pleasure.

BOB GARFIELD: Jeremy Stoppleman is co-founder and CEO of Yelp.