• 
• 3%
• Created over 9 days

We counted 1,880 reviews for this product over the span of 2,369 days, an average of 0.8 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 5 or fewer reviews on any given day.

However, we see the following 9 days exceeding this threshold:

• 8 Reviews on Feb 10, 2016 (Avg. rating: 4.8)
• 7 Reviews on Jan 17, 2016 (Avg. rating: 5.0)
• 7 Reviews on Sep 1, 2015 (Avg. rating: 4.7)
• 6 Reviews on Jan 6, 2016 (Avg. rating: 5.0)
• 6 Reviews on Jan 21, 2016 (Avg. rating: 5.0)
• 6 Reviews on Apr 5, 2016 (Avg. rating: 5.0)
• 6 Reviews on Nov 14, 2018 (Avg. rating: 5.0)
• 6 Reviews on Nov 21, 2014 (Avg. rating: 4.8)
• 6 Reviews on Feb 18, 2016 (Avg. rating: 4.8)
Show All

In total, we found that 58 reviews were created on just 9 days. The reviews on these high volume days have rated this product an average of 4.9 while reviews from other days have rated this product an average of 4.7. 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.

Read more about our Rating Trend 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 4.6, while the average ease score for reviewers in this category is 4.3. 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.

• 
• 29%
• Used substantial repetitive phrases

548 of the 1,880 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.

• 
• 2%
• Unverified Purchases

38 of the 1,880 total reviews for this product are unverified purchases. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

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.

• 
• 30%
• Have an overrepresented word count

In the graph above, we can see the distribution of review word counts for this product and the expected distribution for this category. We see the following 2 groups with a statistically significant greater concentration than what we'd expect to see:

• 0-5 words: 16.5% (Avg. rating: 4.8)
• 6-15 words: 13.5% (Avg. rating: 4.7)

In total, we found that 563 reviews (or 30%) are within an overrepresented word count group. 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 Word Count Comparison test.

One-Hit Wonders

• 
• 3%
• have only posted one review

60 of the 1,880 reviewers have only reviewed this product. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

Never-Verified Reviewers

• 
• 1%
• have zero verified purchases

11 of the 1,880 reviewers have never written a verified purchase review. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

Take-Back Reviewers

• 
• 11%
• have previously deleted reviews

207 of the 1,880 reviewers have had at least one of their past reviews for another product deleted. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

Single-Day Reviewers

• 
• 2%
• have posted all their reviews on a single day

40 of the 1,880 reviewers have written multiple reviews but posted all of them on a single day. 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 Suspicious Reviewers test.

• 
• 18%
• Substantial overlapping review history

337 of the 1,880 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.

Brand Repeaters

We didn't detect a substantial amount of Brand Repeaters.

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.