What the Verified Purchase badge actually tells you
On Amazon, the Verified Purchase badge means Amazon's records confirm the reviewer bought the item through the platform. That raises the evidence quality of a review — the person at least held the product — but it is not a guarantee of honesty. Sellers have been known to refund buyers off-platform in exchange for positive reviews, badge and all.
Reviews without the badge are not automatically fake either; long-time customers sometimes review products bought elsewhere, and Vine reviewers carry a program disclosure instead. Treat the badge as one signal among many: useful in aggregate, weak as a single-review verdict.