Because they have soooo much stuff for sale, Amazon is pretty much a one-stop shop whether you want to research, buy, or price-compare a product of your choosing. If you’re like many people, you probably browse the reviews first before buying from them or elsewhere.

Worthy of tilting your decision towards yes or no, those reviews can mean the difference when it comes to what you buy, who you’re buying it for, and how much you really want to spend on it. If you’re hip to the review game, then you know it is very easy for an Amazon seller to hire people to write glowing testimonials that are all in the 4 or 5-star range.

It’s not fair, but them’s the breaks. We know you’ve seen sketchy writeups, and sometimes photos accompany them. There are some that are totally valid, verified, and spot-on helpful, but how can you tell the real ones from the fake ones?

With these tips from a journalist! Columnist Joanna Stern of the Wall Street Journal caught up with a woman who is a professional Amazon reviewer (yep, it’s a thing), and uncovered some interesting tidbits about the review process.

Her source, Kathleen San Martino, is part of Amazon Vine, a program run by Amazon that lets people select and receive products in exchange for honest reviews. Everything from beauty items to pet beds to electronics are up for grabs through Vine, and people like San Martino can leave whatever number of stars they wish. It may be 1 or it may be 5.

What Stern found out was that even though Amazon has taken steps to crack down on phony reviews, they are still able to slip through. They will often be marked as a “verified purchase” even though the opinion may be untrue.

Sellers and reviewers are linking up in places like Facebook where they make deals. A seller will offer a cash incentive in exchange for a 5-star review. The purchaser will order the item, give it a flattering review with photos, and once the seller has seen it, they’ll typically pay the person through PayPal.

It’s called an incentivized review. If Amazon and Facebook become aware of these violations, they shut down the individuals or groups responsible. In the meantime, what can you do to spot a fake?

San Martino suggests watching out for multiple reviews posted on the same day for a product. If they are all 5 stars, then that’s a red flag. She said to look out for one-liners and the track records of reviewers. If a particular buyer has posted only 5 (or 4) star reviews, it is suspicious.

Stern shared that if you have the time, you can make use of a review authenticator site like Fakespot. Just copy and paste the Amazon URL and it will tell you if the review is “trustworthy”. She also recommends using your own intuition as your best barometer because you can’t believe everything you read.

Amazon relies on algorithms and their own customers to alert them of dubious reviews, so if you see something that doesn’t seem right, say something.

Do you use Amazon reviews to help make buying decisions? Ever been duped? Can you tell if a review is fake or not?