Fake seller and listing fraud in Online marketplaces

How the attack works

1. The operator enters the seller-onboarding flow with multiple identities, aiming to create separate trading accounts that appear unrelated to existing registrations.
2. Automated registration and verification requests repeat through different sessions, with new account details obscuring common device or network context.
3. The accounts publish plausible listings for stock they do not intend to fulfil, using attractive offers to draw buyers towards a purchase.
4. Payments or orders accumulate while each seller profile appears to represent an independent business with its own small set of transactions.
5. Buyers report missing deliveries, and the operator abandons exposed accounts while other registrations or listings continue to attract new purchases.

Why it gets through

A marketplace needs enough seller supply to give buyers choice. That creates pressure to keep onboarding accessible and let new businesses start trading. Fraudsters exploit the same opening, distributing activity across identities so that account-level checks see a series of new sellers rather than a connected effort to collect money without delivering the promised goods.

The risk unfolds across several stages. Registration happens before listings, orders and fulfilment complaints, often in systems owned by different teams. By the time missing deliveries reveal the commercial harm, a trust and safety analyst may have to reconstruct the earlier account creation sequence manually and determine whether other sellers should be reviewed alongside the reported one.

Multiple accounts are not automatically evidence of dishonest selling. Agencies, shared offices and legitimate business groups can produce related device or network signals. Useful investigation combines those relationships with the registration and trading context the marketplace actually holds, rather than treating a matching device or an unfamiliar seller as sufficient reason to close an account.

The buyer refund rate shows how apparently completed orders become failed purchases. Fake sellers can leave buyers without goods while the marketplace attempts to recover money already released under its settlement arrangements. Assess refunds associated with those accounts alongside unresolved orders, rather than treating account removal as the point at which the financial impact ends.

Moderation cost per seller review increases when analysts repeatedly compare registrations, listings and complaints without knowing which activity is related. Time spent rediscovering the same operation reduces capacity for difficult disputes and genuine sellers awaiting approval. Include the work needed after removal, when further complaints or replacement accounts bring the investigation back into the queue.

The repeat purchase rate can suffer when a buyer loses confidence after dealing with a dishonest seller. That hesitation also affects honest businesses trying to establish themselves on the marketplace. Compare whether affected buyers return, using the marketplace’s own customer records, so that acquisition growth is considered alongside the quality and durability of the trading relationships it creates.