How often should you re-check a price?
Refresh cadence should be driven by observed volatility and by what a source costs to read — not by a fixed nightly schedule.
A fixed nightly sweep is wrong in both directions: too slow for the few products that move hourly, and enormously wasteful for the many that have not moved since March.
Drive cadence from observed volatility per listing. A product that changes on most reads earns a short interval; one that never changes drifts toward a ceiling.
Then bound it by cost. Backing off only pays when reading again costs something — for a free source, letting a quiet listing drift saves nothing and loses every short promotion. Free sources should sit near their floor permanently; metered ones should be allowed to drift.
Keep reading
What is commerce intelligence?
Commerce intelligence is the layer above price monitoring: an index of what exists, who sells it, at what, and what that means.
Why percentile beats percent-off
A percentile against a product's own history is a defensible measure of discount depth; percent-off a reference price is not.
Product matching and why it fails quietly
How cross-seller product matching works, the three ways it fails, and why published match confidence matters.
GTIN, UPC, EAN and ASIN
How product identifiers relate, why check digits matter, and what to do when there is no identifier at all.
Data provenance in commerce data
Why every price should carry its origin and a confidence weight, and what goes wrong when it does not.