• 
• 8%
• Created over 8 days

We counted 496 reviews for this product over the span of 7.062 days, an average of 0,1 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 2 or fewer reviews on any given day.

However, we see the following 8 days exceeding this threshold:

• 14 Reviews on Mar 29, 2016 (Avg. rating: 4,5)
• 7 Reviews on Mar 15, 2016 (Avg. rating: 4,3)
• 4 Reviews on Dec 23, 2014 (Avg. rating: 5,0)
• 3 Reviews on Apr 3, 2016 (Avg. rating: 5,0)
• 3 Reviews on Mar 12, 2007 (Avg. rating: 4,7)
• 3 Reviews on Dec 28, 2014 (Avg. rating: 4,3)
• 3 Reviews on Jan 9, 2014 (Avg. rating: 4,0)
• 3 Reviews on Mar 30, 2016 (Avg. rating: 3,7)
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In total, we found that 40 reviews were created on just 8 days. The reviews on these high volume days have rated this product an average of 4,5 while reviews from other days have 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 Rating Trend test.

• 
• 47%
• Unverified Purchases

233 of the 496 total reviews for this product are unverified purchases. The unverified purchasers have rated this product an average of 3,7 while the verified purchasers have rated this product an average of 4,4. 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.

Take-Back Reviewers

• 
• 15%
• have previously deleted reviews

75 of the 496 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.

Single-Day Reviewers

• 
• 3%
• have posted all their reviews on a single day

13 of the 496 reviewers have written multiple reviews but posted all of them on a single day. The Single-Day reviewers have rated this product an average of 4,8 while all other reviewers 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 Suspicious Reviewers test.

Brand Repeaters

• 
• 39%
• Reviewed other products from this brand

191 of the 496 reviewers have reviewed other products for this brand. While this is more Brand Repeaters than we'd expect to see, it does not appear to have a significant impact on the overall rating.

Read more about our Brand Repeats 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 4.3, while the average ease score for reviewers in this category is 4.3. While this discrepancy is rather large, it is not quite large enough to rule out the possibility of it being due random chance.

• 
• 36%
• Used substantial repetitive phrases

177 of the 496 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.

• 
• 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.

• 
• 46%
• Substantial overlapping review history

227 of the 496 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.

• 
• 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.

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. 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 our Deleted Reviews test.