What is Retargeting?

Retargeting (remarketing) shows ads to users who already interacted with a site, app, or contact list but did not complete the target action—or did, for upsell. Audiences are built from pixel data, app events, CRM, or custom audiences.

Mechanics

On a landing visit, a browser pixel or tag marks the user. The ad account builds an audience such as “visitors in the last N days.” A campaign with warmer creative and the same or alternate offer follows the user across social, display, or search partner networks.

In arbitrage

Retargeting raises CR and lowers effective CPA on funnels with longer cycles (finance, e-commerce, subscriptions). Warm traffic converts better than cold. Often combined with lookalikes on conversions: scale cold first, then retarget abandoners.

Settings

Attribution window and membership duration (7, 14, 30, 180 days).
Exclusions: purchasers, bot traffic, GEO mismatch.
Frequency caps to avoid ad fatigue.
Cross-device reach is limited without logged-in users and mobile IDs.

Limitations

Cookie blocking, iOS ATT, and GDPR consent shrink audience reach. Landing pixels must match domain and policy. Retargeting does not replace cold testing—without new users, audiences exhaust. Commerce retargeting: Criteo, Dynamic Product Ads.