Most online reviews are genuine customer testimonies and valuable tools for shopping the internet. But as most shoppers are aware, there are also fake reviews lurking on platforms like Amazon that can throw you off if you aren’t careful. It’s important to evaluate reviews with a wary eye, to learn how to spot fakes, and to make sure, in the end, you use them to help you get what you pay for.

According to the CEO of Fakespot, a free browser extension designed to weed out unreliable product ratings, the number of misleading reviews on Amazon soared in 2020. Fakespot CEO Saoud Khalifah blames the surge in review fraud on Covid-19, which has caused e-commerce to skyrocket and created steep competition for vendors hoping to tap into all that new money coming in.

“This year, starting from lockdown, the numbers exploded,” Khalifah tells CNN Underscored.

It’d be a mistake to take online reviews as gospel and use them as your sole criterion for evaluating the quality of a product or retailer. However, you’d also be remiss to completely ignore online reviews when considering a purchase. Below, we’ve put together a guide that should help you get the most out of reviews so they can be a powerful tool rather than a liability.

First, what is an unreliable review?

There are two main kinds of unreliable reviews. The first are bot reviews. Khalifah says computers spit these out in large numbers around major shopping events like Black Friday. While common, these kinds of reviews are fairly easy for third-party algorithms like Fakespot to find and weed out thanks to their awkward, keyword-studded sentences.

The more insidious variety are promotional reviews, which are written by actual human beings who are compensated behind the scenes in exchange for glowing praise.

Khalifah says this type of review tends to primarily plague phone accessories, electronics and smaller appliances — anything that sellers can order in bulk from a factory. However, no product is immune, especially as more shopping moves online.

How do unreliable reviews work?

“There are hundreds of private groups on social media that solicit paid reviews,” says Tommy Noonan, founder of ReviewMeta.com, another tool that aims to provide customers with more accurate product ratings.

Khalifah calls such arrangements a kind of “review exchange club,” where merchants send free products and other forms of compensation to potential reviewers in exchange for positive write-ups. An Amazon spokesperson confirmed to CNN Underscored, “Bad actors use social media platforms to recruit unsuspecting customers by offering free products and gift cards in return for posting fake product reviews.”

This means that even an Amazon Verified Purchase review can be fake. Some reviewers really are buying products with their own money in order to score that trust-building “Verified Purchase” label, only to be reimbursed or compensated further for writing a positive review after.

It’s worth remembering that getting a product for free doesn’t necessarily mean a review is fake. Someone could be sent a product to review and genuinely think it deserves five stars. Still, soliciting or writing reviews without disclosing compensation expressly violates Amazon’s community guidelines as well as FTC guidelines regarding endorsements within advertising.

“We have clear policies for both reviewers and selling partners that prohibit abuse of our community features,” an Amazon spokesperson told CNN Underscored, “and we suspend, ban and take legal action against those who violate these policies.”

In a statement, Amazon said it utilizes “powerful machine learning tools and skilled investigators to analyze over 10 million review submissions weekly, aiming to stop abusive reviews before they are published. In addition, we continue to monitor all existing reviews for signs of abuse and quickly take action if we find an issue. We also proactively work with social media sites to report bad actors who are cultivating abusive reviews outside our store, and we’ve sued thousands of bad actors for attempting to abuse our reviews systems.”