• 
• 12%
• Created over 17 days

We counted 1,164 reviews for this product over the span of 1,038 days, an average of 1.1 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 6 or fewer reviews on any given day.

However, we see the following 17 days exceeding this threshold:

• 13 Reviews on Apr 5, 2016 (Avg. rating: 4.3)
• 10 Reviews on Feb 4, 2016 (Avg. rating: 4.7)
• 10 Reviews on Apr 18, 2016 (Avg. rating: 4.2)
• 9 Reviews on Oct 26, 2015 (Avg. rating: 4.9)
• 9 Reviews on Mar 30, 2016 (Avg. rating: 4.8)
• 9 Reviews on Oct 21, 2015 (Avg. rating: 4.0)
• 8 Reviews on Mar 31, 2016 (Avg. rating: 4.4)
• 8 Reviews on May 6, 2016 (Avg. rating: 4.4)
• 8 Reviews on Apr 4, 2016 (Avg. rating: 4.3)
• 8 Reviews on Mar 29, 2016 (Avg. rating: 3.9)
• 7 Reviews on Oct 30, 2017 (Avg. rating: 5.0)
• 7 Reviews on Mar 28, 2016 (Avg. rating: 4.9)
• 7 Reviews on Oct 20, 2015 (Avg. rating: 4.7)
• 7 Reviews on Nov 4, 2015 (Avg. rating: 4.7)
• 7 Reviews on Jan 4, 2016 (Avg. rating: 4.4)
• 7 Reviews on Jan 31, 2016 (Avg. rating: 4.0)
• 7 Reviews on Apr 30, 2016 (Avg. rating: 2.6)
Show All

In total, we found that 141 reviews were created on just 17 days. The reviews on these high volume days have rated this product an average of 4.4 while reviews from other days have rated this product an average of 4.1. 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.

Read more about our Rating Trend test.

• 
• 58%
• Unverified Purchases

670 of the 1,164 total reviews for this product are unverified purchases. The unverified purchasers have rated this product an average of 4.5 while the verified purchasers have rated this product an average of 3.6. 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.

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

• 
• 6%
• Admitted to receiving an incentive

68 of the 1,164 total reviews for this product admitted to receiving a free or discounted product in exchange for a review. Incentivized reviews have rated this product an average of 4.7 while reviews that were not incentivized rated this product an average of 4.1. 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.

Read more about our Incentivized Reviews test. Check out our study showing that Incentivized Reviewers are much more likely to leave a positive review.

One-Hit Wonders

• 
• 7%
• have only posted one review

76 of the 1,164 reviewers have only reviewed this product. The One-Hit Wonders have rated this product an average of 3.2 while the reviewers who have posted more than one review have rated this product an average of 4.2. 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.

Never-Verified Reviewers

• 
• 10%
• have zero verified purchases

121 of the 1,164 reviewers have never written a verified purchase review. The Never-Verified Reviewers have rated this product an average of 4.3 while the reviewers who have written at least one verified purchase review rated this product an average of 4.1. 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

• 
• 40%
• have previously deleted reviews

468 of the 1,164 reviewers have had at least one of their past reviews for another product deleted. The Take-Back Reviewers have rated this product an average of 4.5 while the reviewers who don't have any deleted reviews in their history 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.

Read more about our Suspicious Reviewers test.

• 
• 7%
• Used substantial repetitive phrases

78 of the 1,164 total reviews for this product use substantial repetitive phrases between them. These reviewers have rated this product an average of 4.6 while reviews without substantial repetitive phrases rated this product an average of 4.1. 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.

Read more about our Phrase Repetition test.

• 
• 16%
• Substantial overlapping review history

182 of the 1,164 reviewers have substantial overlapping product review history. These reviewers have rated this product an average of 4.6 while the reviewers who have a more unique product review history rated this product an average of 4.0. 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.

Read more about our Overlapping Review History test.

• 13
• Reviews have been deleted

We discovered a total of 13 deleted Reviews for this product, with an average rating of 4.9. Even though deleted reviews don't affect the average rating, the fact that action was taken to delete reviews raises some red flags about the integrity of the reviews for the product as whole.

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 our Deleted Reviews test.

Show distribution of deleted reviews

Brand Repeaters

• 
• 29%
• Reviewed other products from this brand

337 of the 1,164 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

• 
• 2%
• Reviewed mostly products from this brand

24 of the 1,164 reviewers have reviewed multiple products but half or more of their reviews are for this brand. While this is more Brand Loyalists than we'd expect to see, the discrepancy in ratings between the Brand Loyalists and non-loyalists isn't significant enough to rule out the possibility of it being due to random chance.

Read more about our Brand Repeats 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.

• 
• 0%
• From reviewers with an overrepresented participation

We didn't find any participation groups that had a statistically significant greater concentration than what we'd expect to see in this category.
Read more about our Reviewer Participation 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 4.2, while the average ease score for reviewers in this category is 4.3.