When a product review is marked as an "Amazon Verified Purchase," it means that the customer who wrote the review had purchased the item at Amazon.com. Customers may add this label to their review only if we are able to verify that the item being reviewed was purchased at Amazon.com. Customers reading an "Amazon Verified Purchase" review may use this information to help them to decide which reviews are most helpful for their purchasing decisions.
If a review is not marked as an "Amazon Verified Purchase," this doesn't necessarily mean that the reviewer has no experience with the product – it just means that we weren't able to verify that it had been purchased at Amazon. The reviewer may have purchased the item elsewhere or had some other interaction with it. If we could somehow validate his/her experience with the product, we certainly would. The "Amazon Verified Purchase" review label offers an additional way to help gauge the quality and relevance of a product review.
When you write a new review, you will be given the opportunity to mark your review as an "Amazon Verified Purchase." If the tick box doesn't appear, we were unable to verify that you purchased the item at Amazon.
If you wrote a review for an item you purchased at Amazon previously and would like to mark it as an Amazon Verified Purchase, simply edit your existing review and the Amazon Verified Purchase checkbox should appear. After checking the box and saving your review, your review will immediately be marked as an Amazon Verified Purchase. You can also opt to mark all of your past reviews for products purchased at Amazon as Amazon Verified Purchase reviews using the corresponding checkbox during review editing or creation.