Why Two Review Sites Rate the Same Vendor Differently

Short answer: two honest reviews can reach opposite conclusions about the same seller because they measured different things. Before deciding which is right, find out what each one actually scored — the answer is almost always there.

Four reasons the numbers differ

1. Different criteria. A review weighted toward shipping speed and customer service will rank a vendor differently from one weighted toward where a laboratory report resolves. Neither is wrong; they are answering different questions. A reader who wants to know whether the testing is real is poorly served by a score built mostly from delivery times.

2. Different evidence dates. Vendors change. A review that checked a certificate a year ago and one that checked last week can legitimately disagree, and the newer one is not automatically better — it depends whether the thing that changed is the vendor or the checking.

3. One of them is paid. This is common enough in this category to check first. Paid placement is lawful where it is disclosed, and the disclosure is frequently present but buried. Finding it takes a moment and tells you which document you are reading.

4. One of them did not check. The largest source of disagreement is not conflict but absence: one site verified something and the other assumed it. A score with no evidence under it is not a competing measurement, it is a guess with a number attached.

The test that settles it quickly

Open both and look for the evidence under the rating, not the rating.

A review that states what was checked, when, and what was found can be disagreed with on specifics. A review that gives a number and a paragraph of adjectives cannot be checked at all — and an unfalsifiable score is not evidence regardless of which direction it points.

Then ask the awkward question of both: does either one say anything inconvenient about the vendor it rates highest? A review where the favoured vendor has no open items has either found a perfect business or stopped looking.

How this index tries to be checkable

Every rating here names what was examined and when, links the source where one exists, and marks unconfirmed anything that was not verified rather than assuming it. Where a vendor scores poorly the specific finding is stated, and where our own checking is thin we say that instead of implying the vendor is at fault.

That standard applies to the vendor we are affiliated with too. Its laboratory credential is marked unconfirmed on this site, and it scores below another vendor on that criterion, because that vendor's laboratory was checked and ours has not been. A rubric that bends for one entry is not a rubric.

Related: what a vendor score should measure · how to compare two vendors fairly · how to weigh a single bad experience.

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General educational information, not claims about any specific company. For research and educational purposes only. Not medical advice. Some links on this site are affiliate links.