Retargeting

Retargeting is advertising shown to people who have already been to your website or interacted with your business. A visitor arrives, a tag on the page records that they were there, and afterwards your adverts appear to them elsewhere. The mechanism is unremarkable. What makes it worth understanding is that it behaves completely differently from advertising aimed at strangers.

In short

• Adverts shown to people who already visited you.
• The audience is warm, so it usually converts at a better rate than anything else.
• It divides an existing audience rather than creating one.
• Excluding people who already bought is the setting most often forgotten.

Why it performs better than it should

The numbers from a retargeting campaign usually look flattering next to everything else, and it is worth understanding where the flattery comes from before drawing conclusions from it.

The audience is people who already showed interest. They know the name, they have seen the offer, and some of them were going to come back anyway. That last group is the awkward one. When they return and buy, the campaign gets the credit, and some portion of what looks like performance is simply the advertising standing in front of a door somebody was already walking through.

None of that makes it a bad thing to run. It makes the reported return an overstatement, and it is why a business should not conclude from a good retargeting report that advertising in general is working. Those are different audiences answering different questions.

The setting everybody forgets

Somebody buys from you. They are on the list of people who visited the site. The campaign carries on showing them the advert for the thing they now own. This is not a rare misconfiguration. It is close to the default outcome, because the audience is built from visitors and buyers are visitors. Fixing it means building a second audience of people who reached the confirmation page and telling the campaign to exclude them.

That one exclusion does two things at once. It stops the spending that was going nowhere, and it removes the experience that gives this kind of advertising its bad name. If you do nothing else described on this page, do that.

How long to follow somebody

The platforms will let you keep somebody in an audience for a very long time, and the fact that you can is not a reason to.

Set the window against how long the decision genuinely takes in your trade. A lunch decision has a life of days. A quote for building work might sensibly stay warm for six weeks. Beyond the point where the person has obviously decided something else, every impression is spending money to irritate somebody who now associates the feeling with your name.

Frequency capping is the companion setting and it is just as neglected. It limits how many times one person sees the advert in a day or a week. Left uncapped on a small audience, a small campaign can show one person the same image forty times, which is how a business with two hundred site visitors manages to feel inescapable.

What it needs before it can run

The requirements are modest, with one exception that businesses tend to discover after setting everything else up.

• Enough visitors. Retargeting splits traffic you already have. Google now permits audiences from 100 people, and a list that small refills so slowly that the campaign barely runs. If the site is quiet, this is not the work to be doing.
• Tracking installed correctly. A tag on every page, firing, and respecting whatever consent the visitor gave. Covered under tracking.
• Somewhere worth sending people back to. The advert returns somebody to a page they already left once. If nothing about it has changed, the second visit tends to end the same way.

The tracking underneath is shifting

For years this ran on third-party cookies, and for a while the industry expected them to disappear from Chrome. Google announced that plan, then reversed it in 2024, and they remain in place.

The reversal is less reassuring than it sounds. Safari and Firefox have blocked these cookies by default for years, which degraded the part of retargeting that runs across the open web on other people’s sites. It did not make those visitors unreachable, because the large platforms never depended on that mechanism. Meta recognises people through its own apps and its own first-party cookie, and Google recognises people who are signed in. What shrank is the middle of the market, and the practical position is that the audience you can follow is smaller and less evenly distributed than the audience that visited.

What this pushes businesses towards is information they hold themselves: a customer list, an email list, the record of who actually bought. Both major platforms accept uploaded lists as an audience, and that route does not depend on anybody’s browser settings. Two caveats come with it. The minimum list size for matching is considerably higher than the hundred quoted above, so it is not the fallback for a business that could not fill an audience from its site. And it depends on having permission to use the data that way, which is where the privacy obligations start rather than end.

Words you will hear

• Pixel or tag. The snippet on your site that records visits into an audience.
• Audience or list. The group being advertised to.
• Exclusion. An audience deliberately kept out, most usefully buyers.
• Frequency cap. A limit on how often one person sees the advert. Worth setting here, because a retargeting audience reaches an uncomfortable frequency faster than any other.
• Membership duration. How long somebody stays in the audience after their visit.
• Dynamic retargeting. Adverts rebuilt around the specific items somebody looked at. It runs off a product feed, so it applies wherever you have one, which includes property, travel and job listings as well as shops.
• First-party data. Information you collected yourself, such as a customer list. Increasingly the sturdier foundation.

A reasonable starting position

1. Build one audience of people who visited in the last thirty days.
2. Build a second of people who reached the thank you page.
3. Exclude the second from the first.
4. Cap the frequency where the platform lets you, which on some campaign types it will not.
5. Send the traffic to a page answering the objection somebody probably left with, rather than to the homepage.

That configuration takes an afternoon, avoids every failure described above, and is more than most businesses running retargeting today have bothered to do.