Yelp's IPO filing comes hot on the heels of successful IPOs and high valuations for Angie's List and Groupon. Yelp's timing reflects both a tech-friendly market and the company's current position as the dominant consumer-review web site. Yelp has 22 million reviews, and the supposedly imminent onslaught of competing review sites has yet to materialize. But is Yelp really poised for long-run success? My research shows that there are points in its favor — but there are others that should raise investors' concern.
First, the positives:
Yelp works. Yelp is relevant only to the extent that it affects readers' choices of where to go. The evidence shows that it does. In a recent paper, I combined Yelp ratings with restaurant revenues for every restaurant that operated in Seattle during Yelp's entire run there. The data suggest that a one-star increase in a restaurant's Yelp rating leads to a 5% to 9% increase in revenue. How do we know that it is in fact Yelp that matters, and not some other information source? To support the causal inference, I exploited the fact that Yelp rounds ratings to the nearest half-star. I found that restaurants receive a jump in sales after a rating is rounded up. So Yelp is driving sales, at least for independent restaurants. Positive ratings don't help chain restaurants, which already have strongly established brands.
It gets its content for free. Even more impressive than Yelp's impact has been its ability to generate 22 million reviews without paying for them. Yelp has been extremely effective at leveraging social incentives to make people work for free. It created a network of "elite" reviewers, whose reviews tend to be less erratic and closer to restaurants' long-run averages. Yelp hosts special events to reward these prolific reviewers. It's not clear whether upstart review companies would be able to replicate this excitement about reviewing.
Search is moving away from Google. Google recently acquired Zagat, creating a major competitive threat to Yelp. One concern is that Yelp will be hurt as it falls down the Google search rankings (and Yelp acknowledges that most of its search traffic comes from Google). When Yelp began in 2004, this would have been a devastating prospect. And to some extent, it still is. But new ways of searching for products may start to change this dynamic. For example, many people find restaurants on Yelp using smartphone apps, circumventing the standard Google search process. This trend will only increase with time.
Now the factors working against Yelp:
It's easy to write fake reviews. Yelp and Angie's List follow very different business models. Angie's List charges readers to view its content, while Yelp's reviews can be accessed for free (and the company makes money by allowing businesses to advertise). Angie's List has a strict quality assurance process; Yelp lets virtually anyone review. The ease of leaving reviews on Yelp has led to a larger number of reviews, but it has opened the door for businesses to leave fake reviews — for themselves, their friends, and their competitors. In a world where we know who is writing the reviews (your Facebook friend, for example), this is not a problem. In a world where reviewers are fairly anonymous, it is.
Legitimate reviews may be filtered out. More worrisome than the fake-review problem is Yelp's solution: It uses a program to filter out seemingly bogus reviews. This is fine, in principle. But it becomes more troubling when you look at the data. In a recent sample, nearly one out of every five reviews was filtered. Looking only at the five restaurants featured on the front page of Yelp's Boston site, roughly 13% of reviews were filtered out. Worse, the reviews were filtered fairly evenly across the restaurants. This means one of two things: Either all five have been trying to game the system, only to be outfoxed by Yelp, or Yelp's algorithm is so coarse that it wipes out a lot of legitimate reviews. While fake reviews clearly exist, it is unlikely that all of these restaurants have been trying to game the system. Combine that with allegations of Yelp sales staff's being overly aggressive in pushing their paid offering, and Yelp's filter can be all the more frustrating for restaurants. There is no evidence that Yelp favors advertisers, and related lawsuits have been dismissed. However, the filtering process does give credence to concerned business owners who note that legitimate reviews have been filtered from their restaurants.
Recommendations aren't customized. Yelp presents consumers with a restaurant's average rating. So does Netflix, but Netflix recognizes that different people have different tastes. Netflix adjusts the rating you see on the basis of how you rated prior movies, leveraging both your reviews and the reviews of people with similar interests. Netflix even held a contest with a $1 million prize for anyone who could substantially improve its recommendation system. The company can do this because it retains a history of every Netflix movie you've rented or rated. Tailored recommendations would be a greater challenge for Yelp because most people don't log on to Yelp when looking for restaurants. The problem may become more acute because sites such as Facebook can tell you what restaurant you will probably like on the basis of not only your own history, but also according to what your friends like (Facebook has yet to capitalize on this capability). Facebook and Google Plus will become bigger threats if they leverage their ability to customize.
And then there's the small issue of profit. Yelp isn't making one. Most of its revenue comes from advertising, which requires a large sales force. Thus far, there has been no talk of levying an Angie's List-style subscription charge.
Yelp was an early innovator in exploiting the value of consumer opinions, but it now finds itself in an increasingly crowded marketplace surrounded by new competitors — Facebook, Google, and a number of smaller startups. And all of the low-hanging fruit appears to have been picked.