• 
• 16%
• Created over 21 days

We counted 768 reviews for this product over the span of 3,308 days, an average of 0.2 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:

• 13 reviews on Jun 20, 2017 (Avg. rating: 4.9)
• 9 reviews on Jun 22, 2017 (Avg. rating: 4.1)
• 8 reviews on Jun 24, 2017 (Avg. rating: 4.3)
• 8 reviews on Jun 21, 2017 (Avg. rating: 3.9)
• 8 reviews on Jun 28, 2017 (Avg. rating: 3.9)
• 6 reviews on Jul 6, 2017 (Avg. rating: 4.2)
• 6 reviews on Jun 17, 2017 (Avg. rating: 4.0)
• 6 reviews on Jun 27, 2017 (Avg. rating: 4.0)
• 6 reviews on Jun 23, 2017 (Avg. rating: 3.7)
• 5 reviews on Jun 18, 2017 (Avg. rating: 5.0)
• 5 reviews on Jun 26, 2017 (Avg. rating: 4.2)
• 5 reviews on Jun 29, 2017 (Avg. rating: 4.0)
• 5 reviews on Jul 9, 2017 (Avg. rating: 3.8)
• 5 reviews on Jul 2, 2017 (Avg. rating: 3.8)
• 4 reviews on Dec 8, 2016 (Avg. rating: 5.0)
• 4 reviews on Feb 18, 2015 (Avg. rating: 5.0)
• 4 reviews on Jun 16, 2017 (Avg. rating: 4.8)
• 4 reviews on Jun 30, 2017 (Avg. rating: 4.5)
• 4 reviews on Jul 3, 2017 (Avg. rating: 4.5)
• 4 reviews on Jul 5, 2017 (Avg. rating: 4.5)
• 4 reviews on Jul 7, 2017 (Avg. rating: 4.5)
Show All

In total, we found that 123 reviews were created on just 21 days. The reviews on these high volume days have rated this product an average of 4.3 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.

Take-Back Reviewers

• 
• 33%
• have previously deleted reviews

255 of the 768 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

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

12 of the 768 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 3.2 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.

• 
• 6%
• Used substantial repetitive phrases

44 of the 768 total reviews for this product use substantial repetitive phrases between them. These reviewers have rated this product an average of 4.8 while reviews without substantial repetitive phrases 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 Phrase Repetition test.

• 
• 19%
• Substantial overlapping review history

147 of the 768 reviewers have substantial overlapping product review history. These reviewers have rated this product an average of 4.3 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.

• 14
• Reviews have been deleted

We discovered a total of 14 deleted reviews for this product, with an average rating of 4.8. 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 the Deleted Reviews test here.

Show distribution of deleted reviews

• 
• 38%
• From reviewers with an overrepresented participation

We see the following 2 participation groups with a statistically significant greater concentration than what we'd expect to see:

• Reviewers with 1-5 reviews: 12.0% (Avg. rating: 3.7)
• Reviewers with 6-15 reviews: 25.7% (Avg. rating: 3.9)

In total, we found that 289 reviewers (or 38%) 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.

• 
• 2%
• Unverified Purchases

17 of the 768 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.

• 
• 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.

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.

Brand Repeaters

• 
• 5%
• Reviewed other products from this brand

40 of the 768 reviewers have reviewed other products for this brand. 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 Brand Repeats 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

1 of the 768 total reviews for this product admitted to receiving a free or discounted product in exchange for a review. 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 Incentivized Reviews test, or check out our study showing that Incentivized Reviewers are much more likely to leave a positive review.