Counterfeit goods on open marketplaces are addressed through a layered system rather than by inspecting products. Each layer catches a different failure, and each has predictable gaps.
Screening happens before a listing goes live
Automated systems evaluate new sellers and new listings against signals including account history, payment details, pricing anomalies and images matched against known products.
Suspicious listings are blocked or held for review, and accounts sharing identifiers with previously removed sellers are prevented from registering.
Screening at this stage is inexpensive and scalable, which is why it catches the largest volume even though it is the least precise layer.
Brand registries supply the reference data
Rights holders enroll trademarks and product information, which gives the platform authoritative data to match listings against and a channel for reporting.
Enrolled brands can search listings, submit takedown reports and in some programs have infringing listings removed automatically when a match is detected.
The gap is that enrollment requires a registered trademark, so small makers without one have fewer tools available to them.
Test purchases verify what screening cannot
Platforms and brands buy from listings and inspect the goods, since some counterfeits are indistinguishable from photographs and descriptions alone.
Results feed enforcement against the seller and, where the item was warehoused by the platform, against the inventory held.
Test buying is slow and expensive per unit, so it is targeted at high-risk categories and at sellers already flagged by other signals.
Commingled inventory complicates tracing
Where identical items from different sellers are stored together, a unit shipped to a buyer may not have come from the seller listed on the order.
Sellers can opt out of commingling to keep their inventory segregated, and many brands require it precisely to preserve traceability.
This is the mechanism behind reports of counterfeits arriving from a listing that appeared to be the brand's own storefront.
Legal exposure drives the investment
Trademark law and federal statutes on counterfeit trafficking create liability that platforms manage through these programs and through joint enforcement actions with brands.
Legislation has also imposed verification requirements on high-volume third-party sellers, requiring identity and contact information be collected and in some cases disclosed.
A buyer who receives a counterfeit should report it through the platform and to the brand, since both use those reports to target the enforcement layers described here.