Criteo: Retargeting Guide for eCommerce

What is Criteo

Criteo is a commerce media platform specializing in dynamic retargeting. Its technology lets you show personalized ads to users who have visited your online store, featuring the exact products they viewed, added to cart, or complementary items — all generated automatically from your catalog.

Founded in Paris in 2005, Criteo operates in over 100 countries and processes data from more than 35,000 advertisers. Its publisher network reaches 92% of internet users globally, making it one of the retargeting platforms with the widest reach outside of Google and Meta.

The connection to conversion optimization is direct: Criteo recovers users who already showed purchase intent but didn't complete the transaction.

How dynamic retargeting works

The technical flow

Tracking pixel: installed on your site, it records events (visit, add_to_cart, purchase)
Product feed: Criteo ingests your catalog (prices, availability, images) in real time
AI engine: the algorithm selects which products to show each user based on their behavior and that of similar users
Creative optimization: dynamically generates banners with the selected products, optimizing layout, CTA, and format
Bidding: bids in real time across thousands of publishers to show the ad to the user at the optimal moment

Available formats

Format	Description	Primary use
Dynamic retargeting	Banners with viewed products	Recover visitors
Similar audiences	Users similar to your buyers	Acquisition
Customer acquisition	Intent-based prospecting	New customers
Video	Personalized pre-roll and mid-roll	Branding + conversion
Retail media	Ads on marketplaces	Retail visibility

Criteo vs alternatives

Feature	Criteo	Google Ads	Meta Ads	RTB House
Dynamic retargeting	Excellent	Good	Good	Excellent
Network reach	92% of users	~90%	Meta ecosystem	Medium
Predictive AI	Advanced	Advanced	Advanced	Advanced
Creative automation	Yes	Limited	Yes	Yes
Retail media	Yes	No	No	No
Payment model	CPC	CPC/CPM	CPC/CPM	CPC

Criteo stands out when your eCommerce has a large catalog (500+ products) and needs retargeting at scale with dynamic creatives. For smaller catalogs, Google Ads and Meta are usually sufficient.

Integration with CRO strategy

Intent-based segmentation

Criteo lets you create audiences by intent level: visitors who only viewed the homepage (low), who browsed a category (medium), who viewed a product (high), and who added to cart (very high). Each segment requires a different message and investment.

Optimal retargeting window

Data shows that retargeting is most effective within the first 24–72 hours after the visit. After 7 days, ROAS drops significantly. Set up attribution windows and frequency capping to avoid wasting budget on users who no longer have purchase intent.

Sync with on-site CRO

Retargeting works best when the return landing page is optimized. If a user returns to your site via a Criteo ad, the experience must be consistent: same product, same price, and a frictionless checkout. Combining Criteo with on-site personalization multiplies the result.

Excluding buyers

One of the most common mistakes is continuing to show ads for a product the user already bought. Configure post-purchase exclusion and redirect those audiences to cross-sell or upsell campaigns.

Key metrics

ROAS (Return on Ad Spend): minimum target of 4:1 for eCommerce
Average CPC: varies by sector, between €0.10 and €0.50
View-through conversions: Criteo attributes conversions from impressions (not just clicks), which can inflate results if not audited
Frequency: keep it below 3–5 impressions per user per day
Incrementality: measure true lift with holdout tests (a group that doesn't see ads)

Limitations

The view-through attribution model can overestimate real impact
Requires a minimum traffic volume for the algorithm to work (~50K visits/month)
Transparency over where ads appear could be better
There is a minimum monthly spend that excludes smaller brands

Conclusion

Criteo is a powerful tool for recovering high-intent users in large-catalog eCommerce. Its dynamic retargeting and massive reach are especially effective when combined with an on-site CRO strategy that ensures returning users find an optimized experience.

To maximize your retargeting ROI, start by auditing your conversion rate and making sure the on-site experience isn't losing the users Criteo sends back to you.

Adrià Vidal — CRO & Digital Strategy at Boost