• 174
• Reviews have been deleted

We discovered a total of 174 deleted Reviews for this product, with an average rating of 4.2. 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

Single-Day Reviewers

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

75 of the 3,035 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 4.5 while all other reviewers 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.

Read more about our Suspicious Reviewers test.

• 
• 18%
• Used substantial repetitive phrases

538 of the 3,035 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 4.2. 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.

Read more about our Phrase Repetition test.

• 
• 7%
• Created over 30 days

We counted 3,035 reviews for this product over the span of 3,609 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 30 days exceeding this threshold:

• 9 Reviews on Feb 11, 2013 (Avg. rating: 4.8)
• 9 Reviews on Apr 17, 2012 (Avg. rating: 4.2)
• 9 Reviews on Jan 11, 2013 (Avg. rating: 4.0)
• 8 Reviews on Jun 10, 2013 (Avg. rating: 4.8)
• 8 Reviews on Mar 16, 2014 (Avg. rating: 4.5)
• 8 Reviews on Feb 16, 2013 (Avg. rating: 4.1)
• 8 Reviews on Feb 10, 2013 (Avg. rating: 3.9)
• 7 Reviews on Feb 4, 2013 (Avg. rating: 4.6)
• 7 Reviews on Apr 11, 2013 (Avg. rating: 4.4)
• 7 Reviews on Jan 4, 2014 (Avg. rating: 4.3)
• 7 Reviews on Jan 6, 2013 (Avg. rating: 4.1)
• 7 Reviews on May 23, 2013 (Avg. rating: 4.1)
• 7 Reviews on Jan 2, 2014 (Avg. rating: 3.7)
• 6 Reviews on Feb 9, 2013 (Avg. rating: 5.0)
• 6 Reviews on Dec 7, 2012 (Avg. rating: 4.8)
• 6 Reviews on Jan 5, 2013 (Avg. rating: 4.8)
• 6 Reviews on May 1, 2013 (Avg. rating: 4.8)
• 6 Reviews on Dec 15, 2012 (Avg. rating: 4.7)
• 6 Reviews on Mar 1, 2013 (Avg. rating: 4.7)
• 6 Reviews on Apr 3, 2013 (Avg. rating: 4.7)
• 6 Reviews on Oct 6, 2013 (Avg. rating: 4.5)
• 6 Reviews on Sep 26, 2011 (Avg. rating: 4.3)
• 6 Reviews on Feb 13, 2013 (Avg. rating: 4.3)
• 6 Reviews on Mar 4, 2013 (Avg. rating: 4.3)
• 6 Reviews on Jan 8, 2014 (Avg. rating: 4.3)
• 6 Reviews on Oct 6, 2014 (Avg. rating: 4.3)
• 6 Reviews on Dec 14, 2012 (Avg. rating: 4.0)
• 6 Reviews on Feb 18, 2013 (Avg. rating: 4.0)
• 6 Reviews on Mar 20, 2013 (Avg. rating: 4.0)
• 6 Reviews on May 7, 2012 (Avg. rating: 3.8)
Show All

In total, we found that 203 reviews were created on just 30 days. Although any days with a larger number of reviews than expected is suspicious, the discrepancy in ratings from reviews created on these high volume days and reviews created on other days isn't significant enough to rule out the possibility of it being due to random chance.

Read more about our Rating Trend test.

• 
• 10%
• Unverified Purchases

300 of the 3,035 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.

• 
• 1%
• Substantial overlapping review history

34 of the 3,035 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 4.2, while the average ease score for reviewers in this category is 4.2.

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.