• 
• 15%
• Unverified Purchases

118 of the 763 total reviews for this product are unverified purchases. The unverified purchasers have rated this product an average of 2.8 while the verified purchasers have rated this product an average of 3.8. Based on our statistical modeling, the discrepancy in average rating between these two groups is significant enough to believe that the difference is not due to random chance, and may indicate that there are unnatural reviews.

Unverified purchases may be the result of Kindle Unlimited readers, buyers who didn't pay full price, or reviewers who did not purchase the product at Amazon. Read more about our Unverified Purchases test.

Brand Repeaters

• 
• 30%
• Reviewed other products from this brand

230 of the 763 reviewers have reviewed other products for this brand. While this is more Brand Repeaters than we'd expect to see, the discrepancy in ratings between the Brand Repeaters and non-repeaters isn't significant enough to rule out the possibility of it being due to random chance.

Brand Loyalists

• 
• 9%
• Reviewed mostly products from this brand

70 of the 763 reviewers have reviewed multiple products but half or more of their reviews are for this brand. This is an excessively large percentage of Brand Loyalists which may indicate unnatural reviews.

Brand Monogamists

• 
• 3%
• Reviewed only products from this brand

20 of the 763 reviewers have reviewed multiple products, but only for this brand. This is an excessively large percentage of Brand Monogamists which may indicate unnatural reviews.

Read more about our Brand Repeats test.

One-Hit Wonders

• 
• 13%
• have only posted one review

96 of the 763 reviewers have only reviewed this product. While this is more One-Hit Wonders than we'd expect to see, it does not appear to have a significant impact on the overall rating.

Never-Verified Reviewers

• 
• 3%
• have zero verified purchases

24 of the 763 reviewers have never written a verified purchase review. The Never-Verified Reviewers have rated this product an average of 2.5 while the reviewers who have written at least one verified purchase review rated this product an average of 3.7. Based on our statistical modeling, the discrepancy in average rating between these two groups is significant enough to believe that the difference is not due to random chance, and may indicate that there are unnatural reviews.

Take-Back Reviewers

• 
• 18%
• have previously deleted reviews

139 of the 763 reviewers have had at least one of their past reviews for another product deleted. This is an excessively large percentage of Take-Back Reviewers which may indicate unnatural reviews.

Read more about our Suspicious Reviewers test.

• 
• 11%
• Created over 21 days

We counted 763 reviews for this product over the span of 2,746 days, an average of 0.3 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 3 or fewer reviews on any given day.

However, we see the following 21 days exceeding this threshold:

• 5 reviews on Feb 9, 2014 (Avg. rating: 5.0)
• 5 reviews on Feb 1, 2013 (Avg. rating: 4.8)
• 5 reviews on May 13, 2013 (Avg. rating: 4.2)
• 4 reviews on Nov 17, 2018 (Avg. rating: 5.0)
• 4 reviews on Mar 9, 2013 (Avg. rating: 5.0)
• 4 reviews on Jul 30, 2013 (Avg. rating: 5.0)
• 4 reviews on Nov 10, 2013 (Avg. rating: 4.8)
• 4 reviews on Jan 6, 2015 (Avg. rating: 4.8)
• 4 reviews on Jun 1, 2017 (Avg. rating: 4.5)
• 4 reviews on Jan 31, 2013 (Avg. rating: 4.5)
• 4 reviews on Dec 15, 2014 (Avg. rating: 4.3)
• 4 reviews on Jan 2, 2014 (Avg. rating: 4.0)
• 4 reviews on Mar 10, 2017 (Avg. rating: 4.0)
• 4 reviews on Feb 3, 2013 (Avg. rating: 4.0)
• 4 reviews on Dec 27, 2016 (Avg. rating: 3.8)
• 4 reviews on Jan 21, 2017 (Avg. rating: 3.8)
• 4 reviews on Dec 31, 2014 (Avg. rating: 1.8)
• 4 reviews on Sep 17, 2017 (Avg. rating: 1.8)
• 4 reviews on Oct 10, 2016 (Avg. rating: 1.0)
• 4 reviews on Feb 12, 2017 (Avg. rating: 1.0)
• 4 reviews on Feb 24, 2017 (Avg. rating: 1.0)
Show All

In total, we found that 87 reviews were created on just 21 days. Although any days with a larger number of reviews than expected is suspicious, the discrepancy in ratings from reviews created on these high volume days and reviews created on other days isn't significant enough to rule out the possibility of it being due to random chance.

Read more about our Rating Trend test.

• 
• 11%
• Used substantial repetitive phrases

87 of the 763 total reviews for this product use substantial repetitive phrases between them. This is an excessively large percentage which may indicate unnatural reviews.

Read more about our Phrase Repetition test.

• 
• 42%
• From reviewers with an overrepresented participation

We see the following 1 participation group with a statistically significant greater concentration than what we'd expect to see:

• Reviewers with 1-5 reviews: 42.1% (Avg. rating: 3.5)

In total, we found that 321 reviewers (or 42%) are within an overrepresented participation group. While this is more reviews from overrepresented participation groups than we'd expect to see, these reviews do not appear to have a significant impact on the overall rating.

Read more about our Reviewer Participation test.

• 
• 0%
• Have an overrepresented word count

We didn't find any review word count groups that had a statistically significant greater concentration than what we'd expect to see in this category.
Read more about our Word Count Comparison test.

• 
• 12%
• Substantial overlapping review history

91 of the 763 reviewers have substantial overlapping product review history. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

Read more about our Overlapping Review History test.

The ease score is the average rating for all reviews that a given reviewer submits. The average ease score for reviewers of this product is 3.9, while the average ease score for reviewers in this category is 4.1.

On Oct 3, 2016, Amazon prohibited incentivized reviews, however we still test for them since there are still millions in our dataset.

• 
• 0%
• Admitted to receiving an incentive

We didn't detect any reviews that used language indicating they were incentivized.
Read more about our Incentivized Reviews test, or check out our study showing that Incentivized Reviewers are much more likely to leave a positive review.

• 0
• Reviews have been deleted

We have not discovered any deleted reviews for this product.

There are a few limitations to keep in mind regarding the Deleted Reviews test:

1. We don't have a magic ability to collect every single deleted review; we can only identify reviews as deleted if we collect them on one date and then notice they are no longer visible on a subsequent date.
2. We have no information on reviews that were never published in the first place.
3. We also don't know why these reviews were removed. It could be action from the platform, personal decision by the review author, part of an entire account closure, even some data error on our part, etc.

Read more about the Deleted Reviews test here.