That online review may recommend a restaurant in glowing prose, but should you eat up every word? Maybe not.

A months-long investigation by CBC’s Marketplace shows how easy it is for companies to deceive consumers online. It uncovered an entire industry designed to help businesses mislead consumers, bolstering companies’ online reputations with fake reviews and testimonials.

A good online reputation can have a huge impact on a company’s revenue. When researchers at the Harvard Business School analyzed restaurant reviews and revenue in Seattle, they found that a one-star increase on the popular review site Yelp meant a five to nine per cent increase in revenue for independent restaurants.

“Some data now show that a good majority of people in North America believe and trust online reviews more than they trust their friends’ opinions,” Jeff Hancock, a professor who researches online deception at Cornell University in Ithaca, NY, told Marketplace co-host Erica Johnson.

And as the public's reliance on review sites has increased, so has the market for bolstering businesses online reputations.

“I think it’s really amazing how easy it is to purchase deception now on the internet,” Hancock says.

(Watch the investigation, Faking It, on Friday, Nov. 7 at 8 p.m. ET / 8:30 p.m. NT on CBC Television to find out how you can separate review fact from fiction. Join the conversation on Twitter using the hashtag #reviews.)

Faking out the fakers

As many as 15 per cent of online reviews are fake, according to a 2012 study by IT researcher firm Gartner.

For its investigation, Marketplace created a grilled cheese food truck business called “Cheezed Off!” to test how easy it is for a company to artificially boost its reputation online. Cheezed Off! has all the hallmarks of a legitimate online business: A professional website, promotional YouTube video and social media presence.

The company also has glowing online testimonials on popular review sites like Yelp, Google Plus and UrbanSpoon:

“Cheezed Off! has mastered the art of creating the perfect grilled cheese sandwich. I love comfort food and could not pass up an opportunity to try this nostalgic meal from a food truck while in downtown Toronto. I ordered the classic sandwich and my boyfriend ordered the Hellzaoppin sandwich. Both of these were made quickly and tasted absolutely delicious. This food truck knows their way around a grilled cheese,” one reviewer writes.

Hellzaoppin “Just tried Cheezed Off! for the first time and I have to say that I was very pleased. The bread had a very crispy, satisfying crunch, the presentation was very appealing and the taste was, in a word, yummy!,” another reads.

The problem? Cheezed Off! doesn’t actually exist.

The fake Cheezed Off! food truck was a product of clever photography and PhotoShop; its online reputation was purchased from a variety of businesses designed to help companies deceive consumers.

The Marketplace investigation was inspired by a sting set up by the New York state Attorney General that concluded last year. In that operation, investigators posed as a fake yogurt shop and targeted companies that offered to write fake reviews to make the business more appealing to customers. The sting resulted in $350,000 U.S. in fines against 19 companies for false advertising and deceptive business practices.

Industry of deception

A wide variety of internet marketing companies, online reputation firms and freelance reviewers supply fake testimonials to popular review websites for a price.

Marketplace paid as little as $5 for testimonials to be written about its fake business and posted on big review sites Google Plus, Yelp and UrbanSpoon.

While leading review sites say they try to crack down on the practice, only one site detected and removed the fake reviews that Marketplace paid to have posted.

Yelp, the popular review site with 67 million reviews, detected two of three fake reviews posted about the fictitious Marketplace company.

UrbanSpoon and Google did not detect or remove fake reviews posted about Cheezed Off!.

In a statement, Google wrote: “While we take down thousands of false entries each month, there is a small subset of bad apples out there.

“We take verification very seriously and have several processes in place to authenticate businesses and remove false reviews, including a link next to each review allowing users to help flag suspicious reviews for us.”

Fake review problem growing

Hancock says that most of the reviews online are legitimate, but the problem with fake reviews will continue to grow.

“I think it’s going to become increasingly a big problem as more and more these high-end services – lawyers, dentists, doctors – come online with the reviews,” Hancock says.

“That’s not just having a bad meal at a restaurant. That could affect your life in a big way.”

His advice? If you’re going online for advice, sample widely.

“One of the best pieces of advice is to look for lots of different reviews and lots of reviews,” he says.

“Just like you would never just ask one person what they thought of something, you don’t want to rely on one or two reviews. It’s hard to fake hundreds and hundreds of reviews even though they’re so cheap.”