When ordering a bed-in-a-box online became popular a few years ago, grassroots blogs and review sites popped up to evaluate mattresses from Casper, Leesa, Purple, Saatva and others. Consumers liked foam mattress options that were cheaper and easier to buy, deliver and return. They felt more in control.

But an article in "Fast Company" earlier this month called "The War to Sell You a Mattress is an Internet Nightmare" shows how consumers were also being manipulated. It calls out the lengths that online mattress company Casper went to scrub negative reviews. It also exposes reviewers who accepted money from mattress makers for favorable reviews and did not disclose it.

Online reviewers are required to disclose how they get paid in accordance with the Federal Trade Commission's "Guides Concerning the Use of Endorsements and Testimonials in Advertising."

Minneapolis-based mattress reviewer Ben Trapskin said he gets paid about $75 per mattress when a shopper purchases a mattress through a link on SleepSherpa.com, a site he started in 2015. Last year in Edina he opened the country's only online mattress showroom. "It's important that consumers know we get paid affiliates fees," he said. His disclaimer page doesn't mention the amount he gets paid, but, "I only recommend products or services that I use personally and believe will add value to my readers," he said.

In other words, don't look for a negative review on his site. The lowest rated mattress gets a score of 7.9 out of 10. Some reviewers, including Trapskin, have learned that less than enthusiastic reviews can bring a lawsuit. In 2016 Sleepsherpa was one of three websites sued by Casper for alleged false advertising and deceptive practices.

Trapskin's case was settled out of court. "I can't say much about it," he said. "It's fair to say that I won't ever be carrying Casper in the store."

Asked why he doesn't disclose his commission on each brand of mattress that he sells, Trapskin said, "I signed contracts with companies where I'm not allowed to disclose them per terms of my affiliate agreement with them." But based on where the industry is going, more transparency is needed, he said.

His Edina showroom displaying more than 20 online brand mattresses is a partial way to increase transparency. It allows consumers to test mattresses free from ratings or reviews. Online, it's not that simple.

According to the article in Fast Company, reviewers such as Derek Hales, formerly of Sleepopolis, didn't disclose a sum of $40,000 that mattress maker Leesa paid him. The founder of a site called Honestmattressreviews didn't disclose the $150,000 paid to him by mattress maker Ghostbed,

At a time when consumers rely more than ever on reviews from fellow consumers, whether it's on Amazon, Trip Advisor or Sleepopolis, one thing hasn't changed. It's still "buyer beware."