What Is Ad Retargeting? How It Works, What It Costs, and How to Set It Up

Think of retargeting as 80s radio rotation for your brand: the more often people hear the hook, the more likely they are to pick up the record. People who already showed interest convert better than cold audiences, and display, native and video all work for reaching them.

This guide covers how retargeting works, what it costs, which retargeting platform fits which job, and how to use your own audience data.

What Is Ad Retargeting?

Ad retargeting is the practice of serving advertisements to users who have previously visited a specific site. It keeps an advertiser in front of those users on the other sites they visit, so they keep learning about the product, get a reason to buy, or remember it when they’re ready.

What is a retargeting ad?

A retargeting ad is a paid placement shown specifically to users who have already interacted with your brand, visited a page, viewed a product, or abandoned a cart.

In 80's terms, this would be like hearing “The Power of Love” by Huey Lewis on the radio on your way to school, catching the video later on MTV, and then watching the song power Marty McFly to skitch on a garbage truck. (Sorry if we lost a few Zoomers there)

But would “The Power of Love” be as catchy if you heard it on the radio only once? Not a chance. Products work the same way. This is what typically happens to first-time visitors:

How Does Ad Retargeting Work? What Is a Retargeting Pixel?

Retargeting sounds technical, but the idea is simple: retargeted advertising connects a tracking pixel on your site to a DSP, which then bids to show ads to that user wherever they go next.

The process of ad retargeting begins when a user visits a specific website that has added a retargeting pixel. This pixel is a small piece of code designed to capture the viewing activity of everyone who visits a specific site.

That makes placing the pixel, or uploading an audience list, the first step of display retargeting: without it, there’s no segment to target. The pixel is also called retargeting code or a retargeting tag.

The pixel passes session data to programmatic advertising tools so they can show relevant ads. Programmatic retargeting automates the rest: users are sorted into groups and ads are placed in real time, with no manual work. Social platforms such as Meta and LinkedIn also show retargeting ads in users’ feeds, usually at a higher cost per view.

I Want Candy...and Cookies! (Retargeting Ones)

Once a pixel tags a user, it follows their behavior for a set period by placing a small file in the browser, called a cookie. Like a trail of crumbs, the cookie lets the retargeting platform recognize the user later and show them ads from the site that placed the pixel.

Mobile and In-App Retargeting

Mobile ad retargeting works across apps and mobile browsers using device IDs and data users share directly, so it holds up as cookie tracking shrinks. Mobile programmatic retargeting keeps growing because mobile carries most web traffic. In-app audiences can be grouped by device type, operating system, location and past interactions. To follow one person across websites and apps, platforms match logged-in user IDs or, less precisely, a household’s IP address.

So how does retargeting work? Let's check out an example:

Say you browse a few sites about hip, techy ways to make an ancient snack, and an Epom ad shows up: a banner ad retargeting our solutions, a video link to our site, or a text ad about our white label DSP. Then it keeps showing up on other sites. That’s retargeting at work.

Retargeting advertising is a standard line item for brands and agencies, and a majority of businesses use it to recover lost leads. Common retargeting ad examples include:

• a banner showing the exact product a user viewed;
• a video reminder of an abandoned cart;
• a native ad offering a limited-time discount to a returning visitor.

What Are The Benefits of Programmatic Retargeting?

Retargeting reminds people who already showed interest to come back and act. It adds value at each step of a typical online sales cycle:

Cycle Step: First Visit

With endless options for every product, 95% of website visitors don’t convert on their first visit, according to Marketing LTB. Retargeting starts bringing them back and keeps your brand top of mind until they’re ready.

Cycle Step: Search

As visitors keep seeing your ads, more of them come back directly or search for your brand when they’re ready to buy.

Cycle Step: Return to Site

First-visit conversions are hard for most advertisers. Retargeting brings more users back to finish what they started: it raises the share of abandoned carts that get completed from 8% to 26%.

Cycle Step: Purchase

Repeated ads on trusted sites, often with an incentive, remove many barriers to buying. The average CTR of retargeted ads is 0.7%, compared to 0.07% for standard display ads: ten times higher.

Retargeting campaigns that rotate creatives every two to three weeks and use frequency caps of no more than 10 views per month perform significantly better than static, always-on placements.

Are Third-Party Cookies Dead? Retargeting in 2026

No. Google dropped its plan to phase out third-party cookies in Chrome and, in October 2025, retired most of the Privacy Sandbox APIs meant to replace them. Safari and Firefox still block them, and consent rules and ad blockers shrink the pool further, so first-party data (your pixel, CRM lists, logged-in user IDs) is the safer base for retargeting in 2026.

What’s Changing in Retargeting in 2026

Three shifts affect anyone running retargeting this year:

• Pixel-only retargeting is giving way to full-funnel audiences. Classic one-pixel, one-banner tools are repositioning: AdRoll’s 2026 reports frame retargeting as part of a full-funnel strategy, and its display retargeting CPMs swung from +18% early in the year to −29% year on year by September. Treat retargeting as one audience layer, not a standalone channel.
• Meta folds retargeting into automation. In Advantage+ campaigns, custom audiences are suggestions, not hard limits. Since July 2026, users can no longer disconnect their off-Meta activity, so website retargeting pools have grown on their own.
• Retargeting reaches AI answer engines. In February 2026, Evertune launched AI retargeting with The Trade Desk and Index Exchange: brands can buy ads on the pages AI assistants cite, through private marketplace deals available on any DSP.

How to Retarget Your Own Audiences: IP, User ID, ZIP Code and Fingerprint

A pixel only catches people after they land on your site. If you already know your audience (from a CRM, an app, past campaigns or another ad channel), retarget it directly: Epom DSP lets you build retargeting segments from your own data with a pixel or a CSV upload:

Two common setups: fire the Epom DSP pixel on landing pages that get paid social traffic and retarget those visitors on the open web at lower CPMs, or retarget funnel stages, such as users who clicked but didn’t install.

IPs and fingerprints are personal data under GDPR and similar laws, so collect them with consent and check local rules. Apple prohibits fingerprinting in apps, and Safari and Firefox counter it, so use fingerprint segments to support your first-party data, not replace it.

Video Retargeting: When the Higher CPM Pays Off

Video retargeting shows short video ads to people in your segments: someone who browsed your pricing page sees a 15-second video about it, not a static banner. To retarget audiences with video ads, add your segment to a video campaign and pick placements.

Video costs more. Based on Epom observations, video retargeting runs $14 to $17 CPM in North America and Western Europe, about three times display. It earns that premium when there’s a story to tell: video holds attention and explains more in a few seconds.

Video retargeting also runs in more places: pre-roll and mid-roll in publisher players and on CTV, in-banner video in display slots, and outstream video inside articles. The segment stays the same; only the placement changes.

When to use video retargeting:

• Cart abandoners. A 15-second video showing the exact product left in cart, with urgency copy, consistently outperforms static banners for this segment.
• High-consideration purchases. B2B products, SaaS, or high-ticket e-commerce benefit from short explainer retargeting videos that reinforce value.
• Sequential retargeting campaigns. Sequential retargeting shows the same segment as a planned series of ads (an awareness video, then a testimonial, then a product demo), each one moving the user closer to conversion.

Because video CPMs are higher, frequency capping is more important. Based on Epom observations, video retargeting works best at three to five impressions per user per week; beyond that, cost per conversion climbs fast.

Video retargeting runs on VAST tags, the standard that tells a video player how to load and track your creative. For CTV and OTT inventory, check that your DSP or ad server supports VAST 4.x.

CTV and OTT Retargeting

CTV and OTT retargeting works both ways: retarget website visitors on streaming TV, or follow up on phones and laptops with people who saw your TV ad. TVs have no cookies, so both rely on household IP addresses or device IDs, which match households, not individuals. Epom DSP buys CTV inventory, and IP and device ID segments work in CTV campaigns.

How Much Does Retargeting Cost?

In programmatic buying, retargeting ads are traded on CPM, sometimes CPC (the bid is still an estimated CPM). Based on Epom observations, retargeting CPMs in a self-serve DSP run $3–6 for display, $6–10 for native and $14–17 for video in North America and Western Europe.

*Based on Epom data. Stats reflect North American and Western European geos.

Prices also depend on niche, geo and the supply-side platform you buy from. Lower-income countries can cut CPMs by half or more, and a white-label DSP avoids an intermediary’s markup on each CPM you bid.

The most widely used retargeting ad platforms are Google Ads, Meta Ads and programmatic DSPs. The next section compares them.

With CPC, the DSP still bids an effective CPM: CPM = CTR × CPC × 1,000. Google’s average CPCs run $0.66 to $1.23, usually higher than on other DSPs and ad networks.

When to use CPM and when to use CPC?

• CPM is an excellent choice for creatives who deliver CTRs higher than average. If you see one of your campaigns perform well in terms of clicks, always choose CPM.
• CPC caps your cost per click, but the DSP still turns your bid into an effective CPM (CTR × CPC × 1,000). With a low CTR that bid is low, so you win fewer auctions: CPC protects budget at the cost of delivery.

Retargeting Ads Best Practices

A retargeting ads strategy comes down to five choices:

• Segment by intent. Separate cart abandoners, product viewers and blog readers, and give each group its own message and bid.
• Write retargeting ad copy for people who already know you. Remind people what they looked at, give one reason to come back (a discount, a demo slot, free shipping), and use one clear call to action.
• Prepare the common ad sizes. The IAB standard banner sizes cover most retargeting inventory: 300×250, 728×90, 160×600, 300×600 and 320×50 for mobile.
• Cap frequency. Based on Epom observations, no more than 10 impressions per user per month for display and 3–5 per week for video.
• Rotate and exclude. Refresh creatives every two to three weeks.
• Exclude converters with a burn pixel. Fire a burn pixel on your thank-you page and exclude that segment from every retargeting campaign; in Epom DSP, segments can be included or excluded per campaign. Ads shown to recent buyers are the most common retargeting waste.
• Use recency windows. A cart abandoned three days ago and a visit from 30 days ago are different audiences. Split segments by recency (for example, 1–3, 4–14 and 15–30 days) and bid highest on the most recent.
• Check segment size before you launch. Small segments barely deliver, so results never become readable. Google Ads, for example, needs 100 active users before a display remarketing list serves. Merge thin segments or extend the lookback window.

Measure Incremental Lift with a Holdout Group

Retargeting over-credits itself: some of the people it reaches would have bought anyway. To see the real effect, hold out 5–10% of each segment and compare conversion rates. Lift = (exposed rate − holdout rate) ÷ holdout rate. If your platform can’t split a holdout, test by region or show the control group a neutral public-service ad.

How to Choose a Retargeting Platform

An ad retargeting platform is the retargeting software that builds your segments and buys ads to reach them. There are five main types; the right one depends on where your audience is, which formats you need and who owns the data:

Self-serve retargeting suits teams that run campaigns themselves; a white-label DSP suits companies that sell retargeting to clients under their own brand. Epom DSP comes in both versions with the same retargeting tools. If you’d rather not run campaigns at all, retargeting services from agencies or managed DSP teams do it for you, and a DSP buys across many retargeting ad networks at once.

How to Set Up a Retargeting Campaign in Epom DSP

Recently, we made a brief 3-min video that explains both the targeting and retargeting functionality in the Epom DSP. The retargeting part starts at 2:47.

NB: Ad retargeting software ranges from simple pixel managers to full programmatic DSPs with real-time bidding.

If you don't feel like watching the video, this is a brief checklist on how to set up retargeting in our DSP:

1. Go to the retargeting tab and see “Segments.”
2. Here, you can generate a custom code for each segment and use it on your website or give it to your advertiser client to place on other websites.
3. Or upload your own list as a CSV file: IP addresses, user or device IDs, ZIP codes, or IP and user agent pairs.
4. Select the segment in the targeting section while setting a new campaign, and include or exclude a specific group of users.
5. Compare the first ad and retargeting campaign stats in the analytics tab.

"The biggest mistake we see in new retargeting campaigns is skipping audience segmentation entirely, everyone gets the same ad, the same bid, and the same message. Segment by behavior from day one,"

Inga Sydorenko, Head of Media Buying at Epom

Before and After: How an AI Ad Network Fixed Its Retargeting with Epom DSP

A US ad network had built a location AI that spots high-value placements in real time, but its previous DSP held it back. Retargeting was limited: the platform couldn’t segment users well, so audiences were reached once and then lost. Switching was risky, because clients depended on steady delivery.

The team moved to Epom White-Label DSP in under six weeks. In week five, segment retargeting went live: users who interacted with a campaign were collected into segments automatically and re-engaged without manual setup. Even pacing, timezone targeting and an integration with the network’s own AI bidding logic went live in the same rollout.

All puns aside, retargeting works because it reaches people who already know you. Like the 80s song you’re probably humming by now, a good campaign keeps your brand on repeat. Start with a clean segment, cap frequency, rotate creatives every few weeks, and add your own audience data as soon as you have it.

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