Last week, a study from Harvard Business School came out looking at Yelp review fraud, suggesting that about a fifth of Yelp restaurant reviews are fake.

Do you trust reviews you read on Yelp? Let us know in the comments.

It received quite a bit of attention, even making it pretty high on the front page of reddit, where thousands have commented. Among those commenting are some people who claim to have worked at Yelp in the past.

Following is what reddit user ehenningl had to say about the controversial review filter:

As a former employee of Yelp, I was very intrigued by this posting and read through the entire study and while there was some truth to the research they missed some major factors that go into the review filter. First off, Yelp’s review filter is smarter than they think, I don’t know how it exactly works, but it just fucking works. While working at Yelp, I was unable to write reviews for obvious conflict of interest reasons, but wrote many before and after my employment with them.

Most of my reviews would stick because my USER ACTIVITY was frequent on their site and consistently used the site and mobile app to find businesses. The research paper points out; “For example, longer reviews, or reviews by users with a larger review count are less likely to be filtered.” Which is partly correct, but from what I know (they never let us know much about the filter when I worked there) USER ACTIVITY is the #1 factor that goes into the review filter, not the frequency of reviews. Which makes perfect sense because someone who frequents the site would understand the value of the reviews.

The second flaw in their study is “A limitation of our work is that we cannot control for filtering biases in attributes that we do not observe, such as the IP address of a reviewer”, which is probably has the 2nd most weight in the review filter. IP address is everything, especially when you claim that most of these reviews are coming from overseas. For example Yelp knows where my user activity is coming from. If I where to write a review for a random business in Seattle, but I’ve never searched for a business while actually being in the state of Washington, it would most likely be filtered because there hasn’t been any USER ACTIVITY from an IP ADDRESS with in the Seattle area.

The third area that the research didn’t address is the relationship of the reviewer to the business owner. All of my reviews have stuck on Yelp, except one. The one I wrote for a family friends business that I frequent. So how the did Yelp know that I know them personally and filter the review, Facebook. Both my account and the business owners account where linked through Facebook, which we are friends on….boom…filtered.

Now I’m not claiming that 100% of reviews on Yelp are legitimate, but I’m sure as shit 20% are not fake. This study is flawed in so many ways because they didn’t have the proper data set to really understand what goes into the review filter which happens to be Yelp’s greatest proprietary asset.

Yelp has since taken to its blog to address the study, saying that its findings “shouldn’t come as a complete surprise.”

“As consumers increasingly turn to online reviews to find a local business, the incentive to artificially improve one’s reputation also increases,” the company said. “But neither should the fact that Yelp has been on guard against these very same reviews from our earliest days.”

Once again, Yelp pointed to its review filter, sharing the following video from March of 2010:

As you may know, Yelp has often been accused of extortion by small businesses who claim that Yelp buries their positive reviews with the filter if they don’t agree to buy ads from Yelp’s sales force.

Reddit user drkstr17 claims to be a former Yelp employee who used to sell ads for Yelp, calling about 80 local businesses each day. drkstr17 writes:

I’ll be the first to say that it was about the worst job I’ve ever had. It was high pressure sales for very little reward. It was a shit job, but I will say that never once was I given the power to “blackmail” any of my sales prospects. Yes, we were accused of removing good reviews and posting bad ones, but if any other account executives did this, they were merely bluffing. The reviews that get “filtered out” have nothing to do with Yelp sales people. It’s an automated feature that is supposed to detect “shady” accounts in an effort to prevent what this news article posting is all about. It doesn’t do the best job at it; I always thought they could’ve done a much better job with their review filter, but its intentions are in the right place.

Another reddit user suggests that some sales reps could be “very pushy” with prospective clients due to the high pressure sales environment, and make suggestions that were not necessarily in line with company policy. drkstr17 replies:

“Exactly. I’ve actually heard the line, “if you buys ads your reviews would be better” mouthed by several employees. It’s vague enough to be interpreted in different ways. If you do advertise with Yelp, technically speaking, your reach is expanded and your exposure goes up. This would then bring people to your business, and hopefully their experience ends with a positive review. That’s what we were taught to explain to our prospects, but it sounds more enticing to leave it as simple as, “buying ads = more positive reviews.”

Yelp has defended itself against extortion and blackmail accusations, denying all of it, but the accusations have not gone away. The subject even came up on a recent episode of The People’s Court.

It has also come up in Yelp-hosted events, which the company holds around the country to aid local businesses with their Yelp presences.

As far as fake reviews go, Yelp is not taking them lightly. The company has been actively engaged in lawsuits against those creating them. Last week, New York Attorney General Eric T. Schneiderman announced that nineteen companies agreed to stop writing fake Yelp reviews and pay over $350,000 of fines.

“Consumers rely on reviews from their peers to make daily purchasing decisions on anything from food and clothing to recreation and sightseeing,” Schneiderman said. “This investigation into large-scale, intentional deceit across the Internet tells us that we should approach online reviews with caution. And companies that continue to engage in these practices should take note: ‘Astroturfing’ is the 21st century’s version of false advertising, and prosecutors have many tools at their disposal to put an end to it.”

Yelp, in a separate blog post, discussed the AG’s dealings as well.

“We think it’s great the New York Attorney General took action against these businesses that try to mislead consumers. In fact, we helped him,” wrote Yelp Senior Litigation Counsel Aaron Schur. “Because Yelp uses sophisticated software to filter reviews and weed out less reliable ones, we identify — and take action against — concerted campaigns to game the system quite frequently. As a result, we were able to give the NY AG’s office some solid leads on which businesses to go after.”

“And we have more,” he added. “We would love to work with law enforcement officials in other states to crack down on this unethical practice.”

Of course, the site has allowed reviews from Breaking Bad characters to remain on pages for fictional restaurants, but I guess that’s not hurting anybody (except those looking for fictional restaurants to eat at as though they’re real).

As mentioned, there is a massive conversation about Yelp on reddit. To read through the comments, one doesn’t get the sense that Yelp has a very great reputation these days. That hasn’t stopped the company from growing significantly.

As with what you read on Yelp, things we read on reddit often need to be taken with a grain of salt. We don’t have any proof that the comments above are actually from people that worked at Yelp, so take them as you will.

Do you believe Yelp to be a credible source for online reviews? Share your thoughts in the comments.

This article has been updated from its original version.

Images: Yelp