Take-Back Reviewers

• 
• 15%
• have previously deleted reviews

72 of the 490 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

• 
• 4%
• have posted all their reviews on a single day

18 of the 490 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 4.3 while all other reviewers rated this product an average of 3.7. 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 Suspicious Reviewers test.

• 
• 38%
• Substantial overlapping review history

185 of the 490 reviewers have substantial overlapping product review history. These reviewers have rated this product an average of 4.0 while the reviewers who have a more unique product review history rated this product an average of 3.5. 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.

• 
• 13%
• Created over 17 days

We counted 490 reviews for this product over the span of 4,008 days, an average of 0.1 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 2 or fewer reviews on any given day.

However, we see the following 17 days exceeding this threshold:

• 7 Reviews on Nov 1, 2015 (Avg. rating: 3.3)
• 5 Reviews on Jan 9, 2007 (Avg. rating: 4.2)
• 5 Reviews on Jan 19, 2007 (Avg. rating: 4.0)
• 5 Reviews on Oct 22, 2015 (Avg. rating: 3.0)
• 5 Reviews on Oct 27, 2015 (Avg. rating: 3.0)
• 4 Reviews on Nov 8, 2014 (Avg. rating: 4.0)
• 3 Reviews on Jan 10, 2007 (Avg. rating: 4.7)
• 3 Reviews on Feb 15, 2007 (Avg. rating: 4.3)
• 3 Reviews on Oct 29, 2015 (Avg. rating: 4.3)
• 3 Reviews on Jan 14, 2007 (Avg. rating: 3.7)
• 3 Reviews on Feb 20, 2007 (Avg. rating: 3.7)
• 3 Reviews on Oct 31, 2015 (Avg. rating: 3.7)
• 3 Reviews on Jan 17, 2007 (Avg. rating: 3.3)
• 3 Reviews on Feb 6, 2007 (Avg. rating: 3.3)
• 3 Reviews on Jan 13, 2007 (Avg. rating: 2.7)
• 3 Reviews on Feb 11, 2007 (Avg. rating: 2.7)
• 3 Reviews on Nov 2, 2015 (Avg. rating: 2.3)
Show All

In total, we found that 64 reviews were created on just 17 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.

Brand Repeaters

• 
• 26%
• Reviewed other products from this brand

129 of the 490 reviewers have reviewed other products for this brand. While this is more Brand Repeaters than we'd expect to see, the discrepancy in ratings between the Brand Repeaters and non-repeaters isn't significant enough to rule out the possibility of it being due to random chance.

Read more about our Brand Repeats test.

• 
• 37%
• Unverified Purchases

181 of the 490 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.

• 
• 10%
• Used substantial repetitive phrases

51 of the 490 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.

• 
• 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 4.1, while the average ease score for reviewers in this category is 4.3.

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.