Retargeting
Also: remarketing, behavioral retargeting, reciblage, retargeting publicitaire
Showing ads to users who have previously visited your site or interacted with your brand, to bring them back and drive conversion.
What it is
Retargeting (also called remarketing) is an advertising technique that serves ads to people who have already interacted with your brand: they visited your site, viewed a product, added an item to a cart, opened an app, or engaged with your content. Instead of reaching cold, unknown audiences, retargeting focuses spend on warm audiences who have shown intent.
The mechanism relies on an identifier that links a past visit to a later ad opportunity. Historically this was a browser cookie or a tracking pixel. With privacy changes (third party cookie deprecation, iOS tracking limits), it increasingly relies on first party data, hashed email lists, and server side event sharing.
Why it matters
- Higher conversion rates: warm users convert more often than cold prospects, so cost per acquisition is usually lower.
- Funnel recovery: it recaptures abandoned carts and unfinished sign ups.
- Efficient budget use: spend is concentrated where intent already exists.
- Measurable: outcomes tie directly to prior on-site behavior.
The main risks are ad fatigue (over-showing the same ad), wasted spend on users who already purchased, and privacy or consent compliance issues.
How it is used in practice
1. Tag the site or app with a pixel or SDK, or feed events to the ad platform via a server side API.
2. Build audience segments based on behavior: all visitors, product page viewers, cart abandoners, past purchasers.
3. Set exclusions, for example remove users who already converted.
4. Choose the channel: display, social, search (RLSA), video, or email.
5. Cap frequency and set a lookback window (for example 30 days).
6. Measure incrementality, ideally with a holdout group, not just last click attribution.
Worked example
An e-commerce brand gets 100,000 monthly visitors. 3,000 add a product to cart but only 900 buy. The team builds a cart abandoner segment (2,100 users), excludes buyers, and runs a display campaign with a 7 day window and a frequency cap of 3 per day.
- Spend: 4,000 EUR
- Recovered purchases: 210 (10 percent of abandoners)
- Average order value: 60 EUR
- Revenue: 12,600 EUR
A holdout test shows a control group converts at 4 percent unaided, so true incremental lift is about 6 percent, or 126 extra orders. The CFO should credit only that incremental revenue, not all 210, when judging ROI.
See also
Frequently asked questions
What is retargeting?
Retargeting, also called remarketing, is an advertising technique that serves ads to people who already interacted with your brand: site visitors, product page viewers, cart abandoners, app users. Instead of paying to reach cold audiences, you concentrate spend on warm audiences that have already shown intent, which is why cost per acquisition is usually lower.
What is the difference between retargeting and remarketing?
In practice they mean the same thing and the two terms are used interchangeably, along with "reciblage" in French. Historically "remarketing" was Google's label for the feature and "retargeting" the term used by display networks, but no meaningful technical distinction remains. Some teams still reserve "remarketing" for email-based reactivation of existing customers.
Does retargeting still work without third party cookies?
Yes, but the plumbing changes. With third party cookie deprecation and iOS tracking limits, retargeting relies more on first party data, hashed email lists and server side event sharing rather than a browser cookie or pixel alone. The audience logic stays identical; what shrinks is match rate and the reliable lookback window.
Which audience segments should I set up first?
Start with cart abandoners or users who dropped out of a sign-up flow: intent is highest and the message is obvious. Then add product page viewers and all-visitors segments as broader tiers. Always set an exclusion for people who already converted, otherwise you pay to advertise to existing customers.
How do I measure the real ROI of a retargeting campaign?
Use a holdout group and count only incremental conversions, not everything last click attribution hands you. Example: 2,100 cart abandoners, 4,000 EUR spend, 210 recovered orders at 60 EUR average order value, so 12,600 EUR of revenue on paper. If the control group converts at 4 percent unaided, the true lift is around 6 percent, meaning 126 incremental orders, and that is the figure a CFO should judge.