The Sniper Engine

Amazon UK price glitch finder

There is no submission queue here and no editor. A scanner reads Amazon UK price history, scores every listing against its own trading record, and publishes what it finds. Here is exactly how it decides, and where it falls short.

What it compares against

Most deal sites measure a discount against an RRP. That number is chosen by whoever is selling the item, which makes it worth very little — inflate the "was" price and any "now" price looks like a bargain. The Advertising Standards Authority has ruled against the practice repeatedly and it is still everywhere.

This finder ignores RRPs entirely. It uses the item's own average selling price on Amazon UK across the previous 90 days, supplied by the Keepa price-history dataset, and expresses the result as a ratio:

glitch_score = current_price / avg_90

A score of 0.30 means the listing is at 30% of what it has typically been going for — a 70% cut against its own history. The lower the score, the rarer the event. That is the whole idea: a price is only remarkable relative to what that specific product normally costs.

Three tiers

Standard

Cleared the scoring threshold. An ordinary reduction against the item's own 90-day average — worth seeing, not worth rushing.

Glitch

A significant anomaly against that average. Unusual enough to be interesting, not so far out that a mistake is the obvious explanation.

Critical glitch

A probable retailer pricing error. These are also registered for webhook tracking, so we know the moment Amazon corrects the listing. They get their own page.

Tiers are assigned by the pipeline. Nobody can promote a deal between them. See the critical tier on its own.

Where it falls short

It is hourly, not instant. The scan runs against Amazon UK every hour and this page rebuilds at most once every 60 seconds. A glitch that appears just after a scan can go unlisted for the best part of an hour.
A low score is not a guarantee. A product genuinely discontinued and being cleared out scores the same as a mistake. The tier is a probability, not a verdict.
Amazon can cancel a mispriced order. A displayed price is an invitation to treat under UK law, not a binding offer. What you are entitled to.
Amazon UK only. No other retailer is scanned, and prices are in pounds.