Retargeting
Also known as: remarketing, behavioral retargeting, site retargeting
Retargeting (also called remarketing) is an advertising strategy that shows targeted ads to users who have previously visited your website, app, or viewed specific content.
When a visitor lands on your site, a tracking pixel places a cookie on their browser. Ad platforms (Google, Meta, LinkedIn) then show your ads to those cookied users across other websites and social media they visit later. Retargeting is effective because it reaches audiences who have already demonstrated interest in your product -- they know who you are, making conversion more likely than with cold audiences.
Retargeting, explained at three levels
At home
Retargeting is why you see ads for shoes on Instagram after you browsed a shoe website but didn't buy. The shoe website placed a small tracking code on your browser. That code lets Instagram (and other ad platforms) identify you and show you ads for those shoes -- or the shoe brand more generally -- as you browse other websites and apps. Retargeting follows you around the internet to remind you about things you showed interest in.
At work
Most website visitors don't buy on their first visit -- studies suggest 97-98% of first-time visitors leave without converting. Retargeting lets you reach those visitors again after they leave, showing them relevant ads as they browse other sites. Because these users already know your brand and visited your site, retargeting ads typically achieve much higher conversion rates than ads shown to cold audiences who've never heard of you.
At home
Retargeting audience segmentation improves relevance: instead of showing the same ad to everyone who visited your site, segment by behaviour. Visitors who viewed a specific product get ads for that product. Visitors who added to cart but didn't purchase get ads with a discount offer. Visitors who read your blog (but never visited product pages) get ads introducing your product. Different messages for different stages of engagement generate better results than one-size-fits-all retargeting.
At work
Retargeting windows define how long after a site visit a user can be targeted. Standard windows range from 7-90 days depending on the purchase cycle: a $15 product (7-14 day window), a $500 product (30-60 days), and a B2B SaaS decision (90-180 days). Frequency capping in retargeting is critical -- showing the same ad dozens of times per week to a user who has already decided not to buy creates negative brand sentiment and wastes budget. Most practitioners recommend 3-5 impressions per user per week as a starting point.
At home
Cookie deprecation (Chrome phasing out third-party cookies, iOS ATT limiting cross-app tracking) has significantly impacted retargeting capabilities. First-party data retargeting -- using your own CRM email lists uploaded to ad platforms as Custom Audiences -- provides a privacy-compliant retargeting alternative that isn't affected by cookie deprecation. Server-side conversion APIs (Meta CAPI, Google Enhanced Conversions) improve tracking accuracy by sending conversion data server-to-server rather than relying on browser pixels.
At work
Dynamic retargeting (most commonly used in e-commerce) automatically generates personalized ads showing the exact products a user viewed or added to cart, using a product catalog feed. Each ad is dynamically generated for the individual user's browsing history. Platforms like Google's Performance Max and Meta Advantage+ Catalog Ads automate dynamic retargeting at scale. For B2B, account-based marketing (ABM) retargeting targets all known contacts at a target company account rather than individual cookie-based targeting, addressing the limitation that B2B cookies are often on personal devices that don't correlate with work behaviour.
Real-world examples
At home
Aisha browsed a sustainable clothing brand website, looked at several jackets, and left without buying. For the next two weeks, she saw ads for those jackets on Instagram and in Google display ads while reading news sites. When one ad included a 15% first purchase discount, she clicked and bought. The retailer's retargeting campaign had a conversion rate 8x higher than their cold audience campaigns.
At work
Marcus managed a SaaS company's digital advertising. He set up retargeting audiences segmented by funnel stage: visitors who only viewed the pricing page got ads emphasizing ROI and a free trial offer; visitors who started but didn't complete signup got ads with a '5 minutes to set up' message; existing trial users who hadn't upgraded saw ads highlighting premium features. Each segment had a distinct message and separately tracked conversion rate.
Common confusions
- Many users assume retargeting means their device is being listened to or hacked — Retargeting works through tracking cookies and pixels placed on websites you visit, not through microphone or camera access. When you visit a website with a Meta Pixel installed, a cookie is placed in your browser. Meta then recognizes that cookie when you use Facebook or Instagram and shows you ads from that advertiser. This is a transparent (if often surprising) data practice governed by privacy policies, not surveillance of your conversations.
- Some advertisers believe retargeting alone is a complete digital marketing strategy — Retargeting only reaches people who have already found you -- it can't grow your audience or attract new visitors. Retargeting campaigns need a continuous influx of new visitors from prospecting campaigns (search ads, social ads, SEO, content marketing) to maintain a retargeting pool. A business that spends its entire digital advertising budget on retargeting will see diminishing returns as the audience shrinks and saturates.
For analysts
When reviewing a client's paid advertising mix, check the ratio of prospecting (new audience) to retargeting spend. A common error is over-indexing on retargeting (because it shows impressive conversion rates) while under-investing in top-of-funnel prospecting that grows the pool of potential customers. Retargeting amplifies a working acquisition strategy -- it doesn't replace it.
History & origin
Retargeting emerged as a digital advertising capability in the early 2010s, enabled by the widespread adoption of tracking cookies and third-party ad networks. Criteo (founded 2005) pioneered retargeting as a service for e-commerce retailers, showing ads for products users had viewed but not purchased. Google's Remarketing Lists for Search Ads (RLSA, launched 2012) allowed bid adjustments for users who had previously visited your site when they performed subsequent searches. Facebook Custom Audiences (launched 2012) allowed advertisers to target website visitors on Facebook. The iOS 14.5 update (April 2021) and App Tracking Transparency (ATT) significantly disrupted cookie-based retargeting by limiting cross-app tracking on iOS devices, reducing retargeting accuracy for mobile audiences.