• 401
• Reviews have been deleted

We discovered a total of 401 deleted Reviews for this product, with an average rating of 4.6. 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

Never-Verified Reviewers

• 
• 1%
• have zero verified purchases

27 of the 2,359 reviewers have never written a verified purchase review. The Never-Verified Reviewers have rated this product an average of 3.7 while the reviewers who have written at least one verified purchase review 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.

Take-Back Reviewers

• 
• 40%
• have previously deleted reviews

935 of the 2,359 reviewers have had at least one of their past reviews for another product deleted. While this is more Take-Back Reviewers than we'd expect to see, the discrepancy in ratings between the Take-Back Reviewers and reviewers who don't have any deleted reviews in their history isn't significant enough to rule out the possibility of it being due to random chance.

Single-Day Reviewers

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

67 of the 2,359 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 4.4. 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.

Read more about our Suspicious Reviewers test.

• 
• 19%
• 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 1 group with a statistically significant greater concentration than what we'd expect to see:

• 26-40 words: 19.4% (Avg. rating: 4.6)

In total, we found that 457 reviews (or 19%) are within an overrepresented word count group. These reviews have rated this product an average of 4.6, while all other reviews 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.

Read more about our Word Count Comparison test.

• 
• 6%
• Used substantial repetitive phrases

148 of the 2,359 total reviews for this product use substantial repetitive phrases between them. These reviewers have rated this product an average of 4.7 while reviews without substantial repetitive phrases 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.

Read more about our Phrase Repetition test.

• 
• 10%
• Substantial overlapping review history

243 of the 2,359 reviewers have substantial overlapping product review history. These reviewers have rated this product an average of 4.6 while the reviewers who have a more unique product review history 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.

Read more about our Overlapping Review History test.

• 
• 8%
• Created over 33 days

We counted 2,359 reviews for this product over the span of 3,749 days, an average of 0.6 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 4 or fewer reviews on any given day.

However, we see the following 33 days exceeding this threshold:

• 12 Reviews on Dec 8, 2011 (Avg. rating: 4.5)
• 8 Reviews on Sep 14, 2011 (Avg. rating: 5.0)
• 8 Reviews on Jul 27, 2011 (Avg. rating: 4.8)
• 7 Reviews on Dec 27, 2012 (Avg. rating: 5.0)
• 7 Reviews on Jan 22, 2013 (Avg. rating: 4.4)
• 7 Reviews on Nov 25, 2012 (Avg. rating: 4.4)
• 6 Reviews on Aug 10, 2011 (Avg. rating: 5.0)
• 6 Reviews on Sep 1, 2011 (Avg. rating: 4.8)
• 6 Reviews on Aug 18, 2011 (Avg. rating: 4.3)
• 6 Reviews on Oct 28, 2011 (Avg. rating: 4.3)
• 6 Reviews on Dec 3, 2012 (Avg. rating: 4.0)
• 6 Reviews on Apr 13, 2012 (Avg. rating: 4.0)
• 6 Reviews on Oct 9, 2012 (Avg. rating: 3.8)
• 5 Reviews on Jan 4, 2013 (Avg. rating: 5.0)
• 5 Reviews on Nov 22, 2012 (Avg. rating: 5.0)
• 5 Reviews on Nov 29, 2012 (Avg. rating: 4.8)
• 5 Reviews on Aug 23, 2011 (Avg. rating: 4.8)
• 5 Reviews on Dec 12, 2011 (Avg. rating: 4.6)
• 5 Reviews on Jun 14, 2012 (Avg. rating: 4.4)
• 5 Reviews on Mar 4, 2015 (Avg. rating: 4.2)
• 5 Reviews on Jul 17, 2012 (Avg. rating: 4.2)
• 5 Reviews on Nov 2, 2011 (Avg. rating: 4.2)
• 5 Reviews on Oct 19, 2011 (Avg. rating: 4.2)
• 5 Reviews on Aug 7, 2011 (Avg. rating: 4.2)
• 5 Reviews on Dec 21, 2012 (Avg. rating: 4.2)
• 5 Reviews on Jul 20, 2011 (Avg. rating: 4.2)
• 5 Reviews on Aug 17, 2011 (Avg. rating: 4.0)
• 5 Reviews on Jul 24, 2012 (Avg. rating: 3.8)
• 5 Reviews on Jul 15, 2012 (Avg. rating: 3.4)
• 5 Reviews on Aug 5, 2011 (Avg. rating: 3.4)
• 5 Reviews on Aug 3, 2011 (Avg. rating: 3.4)
• 5 Reviews on Dec 26, 2011 (Avg. rating: 3.4)
• 5 Reviews on Nov 12, 2012 (Avg. rating: 2.6)
Show All

In total, we found that 191 reviews were created on just 33 days. Although any days with a larger number of reviews than expected is suspicious, these reviews do not appear to have a significant impact on the overall rating.

Read more about our Rating Trend test.

• 
• 53%
• 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: 25.7% (Avg. rating: 4.3)
• Reviewers with 6-15 Reviews: 27.6% (Avg. rating: 4.3)

In total, we found that 1256 reviewers (or 53%) are within an overrepresented participation group. This is an excessively high number of reviewers in overrepresented participation groups.

Read more about our Reviewer Participation test.

• 
• 3%
• Unverified Purchases

82 of the 2,359 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.

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 4.4.

Brand Repeaters

• 
• 8%
• Reviewed other products from this brand

186 of the 2,359 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 2,359 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. Check out our study showing that Incentivized Reviewers are much more likely to leave a positive review.