Sellers on all sorts of Internet selling sites allege that fake negative reviews hurt sales, while buyers complain that fake positive reviews misrepresent a product or service, each side of the debate with little data to back up either claim—until now. A new study has delved into the horrible world of deceptive online reviewers, finding that sometimes its as bad out there as retailers and consumers imagined. But that most of the time, a negative comment is pretty fair. That's right, as much as we hear the sensationalist stories about how Internet reviewers ruin businesses, on the whole they're not so bad. On the whole, the study clears up a lot of myths about the whole ecosystem.

Myth 1: Fake Reviews Come from Rogue Agents or the Competition

False. There's a perception out there that extreme fake reviews either come from the competition or from customers paid in freebies and deals to say nice things about a company. In the sample, most of the people who wrote deceptive reviews had purchased something from the site—just not the actual product they were reviewing. In other words, they were actual customers. "Instead the low rating effect appears to be due to actual customers engaging in this behavior for their own intrinsic interests," reads the study. "In this respect, the findings represent evidence that the manipulation of product reviews is not limited to strategic behavior by competing firms. Instead, the phenomenon may be far more prevalent than previously thought." 

Myth 2: Most Extreme Negative Reviews Are Fake

False. While 5 percent of the reviews came from customers who hadn't purchased the item in question and fall into the "fake" category, 95 percent of the 325,869 sample were genuine—and not all of them glowing. As the chart below shows, while the fakers (those "without a prior transaction") gave more 1 star ratings, more than 5 percent of "real" people doled out disappointed one-star reviews. 

Myth 3: Most Fake Reviews Are Negative or Extreme

False. While the fake reviewers skew more negative than the real ones, a majority of the fake reviewers still gave a five-star rating, as you can see in that chart above. There's also a good chunk that falls in the two-star to four-star range. Why people want to write middling reviews for products they didn't buy, however, is left unexplained. The researchers suggest some of these people somehow landed on the wrong product page, by accident. Or, perhaps, these people took it to the comments to express general feelings about the brand. 

Myth 4: Fake Negative Reviews Hurt Sales

True. Low-star reviews hurt sales more than higher ones, unfortunately. So, yes, any fake negative reviews—especially the most extreme ones—will result in lower returns. However, that has a "negligible expected impact on a competitor," write the researchers, which is probably why the competition shouldn't spend time spamming the Yelp sections of neighboring establishments.