Zyllion ZMA-16 Handheld Therapeutic Percussion Massager with Heat - One Year Warranty
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Pass Overall Grade
FAIL Rating Trend
FAIL Unverified Purchases
FAIL Word Count Comparison
WARN Deleted Reviews
WARN Suspicious Reviewers
WARN Reviewer Participation
PASS Phrase Repetition
PASS Overlapping Review History
PASS Reviewer Ease
PASS Brand Repeats
PASS Incentivized Reviews
Most Trusted Reviews
Used for back spasms - the heat is great to ... [Go to full review]
Jun 10, 2017
- Verified Purchaser
- Critical Reviewer (avg. rating: 3.0)
Least Trusted Reviews
Nice product! Feels good! Sturdy. [Go to full review]
Mar 5, 2015
- Unverified Purchaser
- Overrepresented word count (5 words)
- Brand Repeater (2 of 7 reviews for this brand; avg rating: 4.5)
- Overrepresented Participation (posted 7 reviews)
- Easy Grader (avg. rating: 4.9)
Fail Rating Trend
- Created over 2 days
We counted 424 reviews for this product over the span of 2,154 days, an average of 0.2 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 3 or fewer reviews on any given day.
However, we see the following 2 days exceeding this threshold:
Fail Unverified Purchases
20 of the 424 total reviews for this product are unverified purchases. The unverified purchasers have rated this product an average of 4.6 while the verified purchasers have rated this product an average of 4.0. 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.
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.
Fail Word Count Comparison
- 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:
Warn Deleted Reviews
We discovered a total of 15 deleted reviews for this product, with an average rating of 4. 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:
- 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.
- We have no information on reviews that were never published in the first place.
- 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.
4.0 average rating of deleted reviews
Show distribution of deleted reviews
Warn Suspicious Reviewers
140 of the 424 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.
Warn Reviewer Participation
- 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:
Pass Phrase Repetition
- Used substantial repetitive phrases
0 of the 424 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.
Read more about our Phrase Repetition test.
Pass Overlapping Review History
Reviewers of this product have ALSO reviewed the following products:
32 of the 424 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.
Pass Reviewer Ease
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.
4.2 Product's Average Ease Score
4.3 Category's Average Ease Score
Read more about our Reviewer Ease test.
Pass Brand Repeats
10 of the 424 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.
Pass Incentivized Reviews
On Oct 3, 2016, Amazon prohibited incentivized reviews, however we still test for them since there are still millions in our dataset.
1 of the 424 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.