• 
• 89%
• Created over 6 days

We counted 204 reviews for this product over the span of 209 days, an average of 1.0 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 6 or fewer reviews on any given day.

However, we see the following 6 days exceeding this threshold:

• 56 Reviews on Mar 7, 2016 (Avg. rating: 4.2)
• 50 Reviews on Mar 9, 2016 (Avg. rating: 4.4)
• 25 Reviews on Mar 8, 2016 (Avg. rating: 4.2)
• 24 Reviews on Mar 11, 2016 (Avg. rating: 4.1)
• 14 Reviews on Mar 10, 2016 (Avg. rating: 4.2)
• 12 Reviews on Mar 12, 2016 (Avg. rating: 4.3)

In total, we found that 181 reviews were created on just 6 days. This is an excessively high number of reviews submitted on these high volume days.

Read more about our Rating Trend test.

• 
• 85%
• Unverified Purchases

174 of the 204 total reviews for this product are unverified purchases. This is an excessively large percentage of unverified purchases and it may indicate unnatural reviews.

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.

On Oct 3, 2016, Amazon prohibited incentivized reviews, however we still test for them since there are still millions in our dataset.

• 
• 29%
• Admitted to receiving an incentive

59 of the 204 total reviews for this product admitted to receiving a free or discounted product in exchange for a review. This is an excessively large percentage of incentivized reviews which may indicate unnatural reviews.

Read more about our Incentivized Reviews test. Check out our study showing that Incentivized Reviewers are much more likely to leave a positive review.

Never-Verified Reviewers

• 
• 25%
• have zero verified purchases

50 of the 204 reviewers have never written a verified purchase review. While this is more Never-Verified Reviewers 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

19 of the 204 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.

Read more about our Suspicious Reviewers test.

• 
• 43%
• 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 2 groups with a statistically significant greater concentration than what we'd expect to see:

• 6-15 words: 20.1% (Avg. rating: 4.3)
• 41-65 words: 22.6% (Avg. rating: 4.0)

In total, we found that 87 reviews (or 43%) are within an overrepresented word count group. While this is more reviews from overrepresented word count 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 Word Count Comparison test.

• 
• 22%
• Used substantial repetitive phrases

45 of the 204 total reviews for this product use substantial repetitive phrases between them. While this is more than we'd expect to see, it does not appear to have a significant impact on the overall rating.

Read more about our Phrase Repetition test.

• 
• 52%
• Substantial overlapping review history

107 of the 204 reviewers have substantial overlapping product review history. While this is more than we'd expect to see, the discrepancy in ratings between these reviewers and reviewers who have a more unique product review history isn't significant enough to rule out the possibility of it being due to random chance.

Read more about our Overlapping Review History test.

• 
• 81%
• From reviewers with an overrepresented participation

We see the following 1 participation group with a statistically significant greater concentration than what we'd expect to see:

• Reviewers with 6-15 Reviews: 80.9% (Avg. rating: 4.3)

In total, we found that 165 reviewers (or 81%) 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.

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

We didn't detect a substantial amount of Brand Repeaters.

• 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.