Blast to the past: Amazon purges old incentivized reviews

Last month, Amazon announced an update to its community guidelines that was intended to end incentivized reviews for all products other than books.

At the time, Amazon’s VP of Customer Experience, Chee Chew, stated that these reviews “make up only a tiny fraction of the tens of millions of reviews on Amazon” and acknowledged that “they can be helpful to customers by providing a foundation of reviews for new or less well-known products.”

But Amazon’s decision to ax them could be based on the fact that, according to a study conducted by, since February, incentivized reviews “[made] up the majority of all new reviews on Amazon” and were much less likely to be critical or negative than their non-incentivized counterparts.


Given that incentivized reviews were not forbidden until its recent announcement, Amazon was not expected to take action retroactively against past incentivized reviews unless deemed “excessive” or out of compliance with the prior policy’s fine print.

But according to new data released by, which analyzed more than 65 million reviews across 32,000 products, Amazon has deleted more than half a million reviews, nearly three-quarters of which were incentivized.

That has apparently reduced the overall percentage of reviews that are incentivized substantially. Across a sample of 10 million reviews, says that just 1.5% are incentivized in the past two weeks, “considerably less” than before.

The impact on retailers

According to TechCrunch’s Sarah Perez, “The average rating for these deleted reviews was 4.75 stars – clearly much higher than the typical average,” and in extreme cases, some products had hundreds or thousands of reviews removed.

While Amazon’s retroactive crackdown on incentivized reviews would seem to be bad news for retailers who have relied on this technique in the past, particularly with the holiday shopping season now underway, the actual impact could be muted.

That’s because despite the large number of reviews that Amazon has deleted, CTO Tommy Noonan says that Amazon’s overall product ratings have not changed much, suggesting that Amazon’s product ratings, which are calculated using machine learning and displayed prominently on product pages, had already been filtering out incentivized reviews pre-purge.

That overall product ratings appear to be in most cases unaffected is good news for retailers, but retailers that have relied heavily on incentivized reviews in the past will need to revisit their Amazon strategies as’s Noonan concludes that Amazon has “effectively killed” the incentivized review industry.

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