Retargeting: how does ad retargeting work?

What is retargeting?

Retargeting is a targeted advertising technique aimed at people who have already shown interest in a brand. In French, the CNIL calls it “reciblage”.

Example: a visitor adds a pair of shoes to their cart, then leaves without paying. They later see an ad for that product on another website. Google Ads gives this case: targeting people who added items to their cart without buying.

Retargeting is one of the uses of display advertising, covered together with programmatic advertising in our guide.

Retargeting vs remarketing: what is the difference?

In practice, none: both words describe the same ad retargeting. “Remarketing” was the name of the feature at Google. The Google Ads Help states that “‘remarketing’ is now referred to as ‘your data’”.

No standard definition separates the two words. Three uses circulate among professionals:

This article uses both words as synonyms, in the advertising sense; email follow-ups follow other rules, covered below. Data segment, customer list and consent mode are defined in our SEA glossary.

How does retargeting work?

Retargeting follows a four-step loop.

1. The tag: the website installs the platform’s code (Google tag, Meta pixel, LinkedIn Insight Tag). In France, it must only fire after the visitor agrees in the consent banner.
2. The segment: the platform adds the visitor to an audience defined by the advertiser (all visits, a product page, a cart), for a chosen duration.
3. Delivery: the ad is shown to this person on the sites and apps of the platform or its partners, such as the Google Display Network.
4. The return visit: the ad sends the person back to the website, where the measurement tool does or does not attribute the conversion to the campaign.

Two variants extend this loop. Google Ads dynamic remarketing shows the products or services viewed in the ad, based on a product feed (.csv, .tsv, .xls or .xlsx file). Customer lists start from contact details uploaded by the advertiser. They depend on the quality and compliance of your customer data.

Standard Universal Analytics properties have not processed data since July 1, 2023. Retargeting audiences are therefore created in Google Analytics 4 or in Google Ads.

Does retargeting work without third-party cookies?

Yes, in part: ad platforms where the user is logged in (Google, Meta, LinkedIn) and first-party data, collected with consent, take over from the third-party cookie.

Google Ads even adapts its frequency capping: without a third-party cookie, it estimates impressions with first-party cookies.

Which platforms can you use for retargeting?

Google Ads, Meta and LinkedIn each have their own retargeting, with their own thresholds and durations. Values noted on October 19, 2026 in Google and LinkedIn help pages; they change.

At Google, the minimum segment size also depends on the segment’s age. A customer list uploaded before February 1, 2024 must still have 1,000 matched users. Data segments can be added to Display, Search or video Google Ads campaigns.

In Performance Max, your audiences only serve as signals: the campaign can reach other people. Only data segments and custom segments can be excluded there.

At LinkedIn, activating a website audience can take longer than the chosen window. Custom audiences on social ad platforms are covered in our social ads guide. Elev8 Lab has no commercial relationship with the vendors mentioned.

What does the law say about retargeting in France?

Retargeting is allowed in France, but it first requires the visitor’s consent to advertising trackers, collected before they are placed. This rule comes from Article 82 of the French Data Protection Act (loi Informatique et Libertés), which transposes Article 5(3) of the ePrivacy Directive (2002/58/EC).

The CNIL’s guidelines and recommendation, adopted on September 17, 2020 and published on September 29, 2020, set the conditions:

• Positive action: simply continuing to browse does not count as consent.
• Refusal just as easy: refusing must be as easy as accepting, and withdrawing consent as easy as giving it.
• Each site: when trackers follow browsing on other sites, the CNIL recommends collecting consent on each of them.
• Proof: organizations must be able to prove valid consent at any time.

The CNIL lists personalized advertising cookies among those that require this prior consent. When a publisher lets an ad network read the cookies placed on its site, both are deemed joint controllers of the processing.

Google also requires advertisers to obtain the consent of users in the European Economic Area, the UK and Switzerland, or risk limited access to its products. Its consent mode passes this choice on to the tags, without providing a banner. Google restricts remarketing in sensitive categories: health, negative financial status, religious beliefs, sexual orientation, gambling or alcohol, among others.

Who must prove consent?

The controller of the advertising processing must be able to prove consent, even when its partners collect it. The Conseil d’État, France’s highest administrative court, confirmed this in 2026 in the Criteo case.

The CNIL’s list is now anonymized: Criteo itself disclosed the sanction, received on June 21, 2023, to the SEC, the US securities regulator.

The Conseil d’État rejected Criteo’s appeal on March 4, 2026 (decision no. 482872). The company processed data on internet users of its partners’ websites without being able to demonstrate their valid consent. The contracts that entrusted this collection to the partners do not exempt it.

Before signing with a retargeting provider, ask how it proves the consent of the people it retargets, site by site.

Can you send an abandoned cart email?

Yes, but not freely. For the CNIL, a cart reminder email is promotional: it falls under Article L34-5 of the French Postal and Electronic Communications Code and requires the recipient’s prior consent.

According to the CNIL FAQ of July 22, 2026, a tracking pixel placed in this email cannot be exempted from consent either. The recommendation on pixels was published in the French Official Journal (Journal officiel) on April 14, 2026.

The “customer” exception covers an existing customer and products similar to those already supplied; simply creating an account is not enough. The email marketing rules (consent, customer exception, pixels) are detailed in our guide.

How do you build a retargeting campaign?

A retargeting campaign is built in seven steps, and its settings follow from your purchase cycle.

1. Check data collection: the tag only fires after acceptance, refusing is as easy as agreeing, and you can produce proof of consent.
2. Split the audience by level of interest: a visit, a viewed product page, an unpaid cart and a customer call for different messages and different durations. Each segment must reach the platform’s threshold.
3. Match the duration to the time to purchase: measure the time between first visit and purchase in your analytics tool, then set the segment duration. Google’s 540 days are a ceiling, not a recommendation.
4. Remove buyers: exclude people who have just bought from your follow-up segments, unless you are offering them something else.
5. Cap exposure: in a Google Ads Display campaign, set a maximum number of impressions per day, per week or per month for the same person.
6. Adapt the ad and the landing page: the page must remove the obstacle from the first visit. This is conversion rate work.
7. Test before scaling up: compare an exposed group with a control group (see the next section).

No “standard” duration or frequency is given here: no primary source with a method sets one. The right values are the ones your data justifies.

How do you measure the real effect of retargeting?

By comparing sales, not attributed conversions. A person exposed to a retargeting ad who then converted may already have made up their mind. The platform attributes the conversion to the ad without proving that the ad caused it.

Only a test with a control group measures the actual effect: part of the audience sees the ads, the other part does not, and the difference in sales shows what the campaign brings. Google itself presents incrementality as the measure of cause and effect, and attribution as a distribution of credit across touchpoints (Google Ads Help, November 11, 2025).

On the attribution side, Google Ads no longer supports the linear, time decay, first click and position-based models. Choosing an attribution model is covered in our web analytics guide.

What are the limits of retargeting?

Retargeting does not create demand: it only reaches people who have already visited, and only some of them.

• A smaller audience: refused trackers, third-party cookie blocking in Safari and Firefox, and the chosen duration remove visitors from the segment.
• Thresholds to reach: a small website may never gather 100 active users at Google, or 300 members at LinkedIn, for a narrow segment.
• Ad pressure: without a frequency cap or buyer exclusion, the same ad follows the same person.
• Dependence on acquisition: the volume you can retarget depends on the traffic brought in by other channels.

Retargeting therefore complements the campaigns that attract new visitors; it does not replace them.