• 837
• Reviews have been deleted

We discovered a total of 837 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 the Deleted Reviews test here.

Show distribution of deleted reviews

• 
• 17%
• Created over 38 days

We counted 2,496 reviews for this product over the span of 1,212 days, an average of 2.1 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 8 or fewer reviews on any given day.

However, we see the following 38 days exceeding this threshold:

• 16 reviews on Feb 2, 2016 (Avg. rating: 4.9)
• 16 reviews on Feb 5, 2016 (Avg. rating: 4.9)
• 16 reviews on Feb 1, 2016 (Avg. rating: 4.6)
• 14 reviews on Jan 11, 2016 (Avg. rating: 4.9)
• 14 reviews on Jan 29, 2016 (Avg. rating: 4.5)
• 14 reviews on Jan 27, 2016 (Avg. rating: 4.4)
• 13 reviews on Jan 12, 2016 (Avg. rating: 4.8)
• 13 reviews on Jan 15, 2016 (Avg. rating: 4.7)
• 13 reviews on Jan 26, 2016 (Avg. rating: 4.7)
• 12 reviews on Jan 28, 2016 (Avg. rating: 4.8)
• 12 reviews on Feb 7, 2016 (Avg. rating: 4.5)
• 11 reviews on Feb 16, 2016 (Avg. rating: 5.0)
• 11 reviews on Jan 16, 2016 (Avg. rating: 4.9)
• 11 reviews on Feb 6, 2016 (Avg. rating: 4.8)
• 11 reviews on Jan 25, 2016 (Avg. rating: 4.8)
• 11 reviews on Feb 3, 2016 (Avg. rating: 4.6)
• 11 reviews on Jan 24, 2016 (Avg. rating: 4.6)
• 11 reviews on Jan 18, 2016 (Avg. rating: 4.6)
• 10 reviews on Jan 19, 2016 (Avg. rating: 4.9)
• 10 reviews on Dec 8, 2015 (Avg. rating: 4.9)
• 10 reviews on Dec 15, 2015 (Avg. rating: 4.9)
• 10 reviews on May 31, 2016 (Avg. rating: 4.6)
• 10 reviews on Feb 9, 2016 (Avg. rating: 4.4)
• 9 reviews on Jun 27, 2017 (Avg. rating: 5.0)
• 9 reviews on Jan 20, 2016 (Avg. rating: 5.0)
• 9 reviews on Jan 5, 2016 (Avg. rating: 5.0)
• 9 reviews on Nov 19, 2015 (Avg. rating: 5.0)
• 9 reviews on Jan 23, 2016 (Avg. rating: 4.9)
• 9 reviews on Feb 4, 2016 (Avg. rating: 4.9)
• 9 reviews on Nov 7, 2015 (Avg. rating: 4.9)
• 9 reviews on Nov 21, 2016 (Avg. rating: 4.9)
• 9 reviews on Jan 30, 2016 (Avg. rating: 4.8)
• 9 reviews on Nov 17, 2015 (Avg. rating: 4.8)
• 9 reviews on Oct 28, 2015 (Avg. rating: 4.8)
• 9 reviews on Jan 13, 2016 (Avg. rating: 4.7)
• 9 reviews on Jan 17, 2016 (Avg. rating: 4.6)
• 9 reviews on Jun 20, 2016 (Avg. rating: 4.6)
• 9 reviews on Jan 22, 2016 (Avg. rating: 4.4)
Show All

In total, we found that 415 reviews were created on just 38 days. The reviews on these high volume days have rated this product an average of 4.8 while reviews from other days have rated this product an average of 4.6. 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.

Read more about our Rating Trend test.

One-Hit Wonders

• 
• 25%
• have only posted one review

618 of the 2,496 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.

Take-Back Reviewers

• 
• 9%
• have previously deleted reviews

236 of the 2,496 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 4.7 while the reviewers who don't have any deleted reviews in their history have rated this product an average of 4.6. 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.

Read more about our Suspicious Reviewers test.

• 
• 5%
• Unverified Purchases

133 of the 2,496 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.

• 
• 3%
• Used substantial repetitive phrases

65 of the 2,496 total reviews for this product use substantial repetitive phrases between them. 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 Phrase Repetition test.

• 
• 5%
• Substantial overlapping review history

126 of the 2,496 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.

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 4.5, while the average ease score for reviewers in this category is 4.5.

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

3 of the 2,496 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.