Audiences, reciblage et data brokers

Beyond single pixels, ad ecosystems build lists — people who visited a product, lookalikes of buyers, uploaded customer emails — and auction ads in milliseconds using IDs synced across networks.

Fingerprint pattern representing stitched audience profiles

Reciblage et audiences similaires

Retargeting shows you the same product ad after you leave a shop. A pixel or tag adds your browser or account to a remarketing list.

Lookalike audiences target people statistically similar to a brand's customers — which is why you see ads for products you never searched for.

RTB, synchro cookies et courtiers

In real-time bidding (RTB), ad exchanges pass bid requests containing cookie IDs, coarse location, and page context. Cookie syncing maps IDs between networks so the same person can be recognized across bidders.

Data brokers (Acxiom, Experian marketing arms, loyalty programs) sell or license segments — auto intenders, new parents, high income — merged with online IDs when hashes match.

Techniques de construction d'audiences

Limites des tests navigateur seuls

Audience membership lives in ad platforms, not in your browser. Our tool shows signals that feed those lists — cookies enabled, fingerprint stability, IP location.

Tester fingerprint et cookies

Tester fingerprint et cookies

Questions fréquentes

Why the same ad on every site?

Classic retargeting — a brand paid to follow its remarketing list across many publishers until the campaign ends or you convert.

Can I opt out of data broker lists?

Some brokers offer opt-out portals (e.g. US state privacy laws). Online ad settings (Google, Meta) limit personalization but do not erase all data.

What is a hashed email upload?

Advertisers send SHA-256 hashes of customer emails to a platform. When you log in with a matching email, you join their custom audience.

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