1. Match the same product
We use available identifiers such as GTIN, UPC, EAN, MPN, model number, brand, generation, capacity, and specifications to group equivalent listings. When identity is uncertain, offers should not be merged merely because their titles or photos look similar.
2. Normalize condition without erasing detail
Seller language is mapped into broad comparison groups such as New, Open box, Refurbished, Used, and As-is. The original seller condition, notes, and grading language should remain available because an open-box return and a store display may carry different risks even when they share a category.
3. Compare the known total
The comparison total begins with item price plus known shipping and mandatory charges. Taxes are labeled separately when a precise destination total is unavailable. Missing accessories, subscriptions, pickup distance, and installation may not be machine-readable, so ItemPrism surfaces them as decision context rather than pretending they are zero.
4. Show protection and seller context
Warranty provider, return window, final-sale status, seller identity, seller rating, and listing freshness can change the practical value of an offer. These factors remain visible rather than being compressed into an unexplained badge.
5. Keep commercial relationships clear
ItemPrism may earn a commission from qualifying purchases after a user follows an approved merchant link. Commissionable links are disclosed. Sponsored placements, if introduced, will be labeled and separated from independent comparison factors. Program availability or commission amount does not change the factual price, condition, or seller information received from a source.
6. Refresh, expire, and correct data
Offers are timestamped and refreshed according to source limits. Expired or unavailable offers should be removed from active comparisons. Users should always verify final price, availability, condition, warranty, and returns on the merchant site because data can change between checks.