Retargeting, also called remarketing, shows ads to people who have already interacted with your business, for example by visiting your website. Done well, it reminds interested people of something they already considered. Done badly, it follows people around the internet with the same ad until they resent the brand. A responsible strategy sets sensible audience windows, caps how often people see ads, avoids sensitive targeting and is open about data use.
How retargeting works
A visitor lands on your site and a tag or pixel from an ad platform records that visit in an audience. The platform can then show your ads to people in that audience on its own properties or partner sites. Platforms call these audiences by different names. Google Ads, for instance, calls them data segments, and lets you build them from website visitors, app users or your own customer lists.
Three things determine what the audience contains: who gets added (which pages or actions), how long they stay (the window), and what you show them.
Choosing audience windows
The window is the number of days someone stays in the audience after their last visit. Google’s documentation says the default membership duration is 30 days for both Display Network and Google Search segments, with a maximum of 540 days, and that each visit resets the clock. It advises choosing a duration related to how long you expect your ads to be relevant for visitors, which it suggests should be similar to your sales cycle.
That gives a practical rule: match the window to how people buy.
| Buying pattern | Sensible window to test | Why |
|---|---|---|
| Impulse or low-cost purchases | Short | Interest fades quickly |
| Considered purchases (services, courses, larger items) | Medium to long | Decisions take weeks |
| Seasonal or event-based offers | The season | Ads lose relevance afterwards |
Treat any specific number as something to test rather than a standard. Changing a window applies to everyone already in the audience, and Google notes that shortening it can remove current members.
Layer audiences by intent
Not every visitor is equal. Build segments such as:
- All visitors: broad reminders, short window, light frequency.
- Viewed a service or product page: more specific messages.
- Started but did not finish an enquiry or checkout: the strongest intent, with a helpful nudge.
- Converted: exclude them from sales ads, or move them to a different message such as a thank-you or an add-on.
Excluding converters is one of the simplest ways to cut wasted spend and annoyance. Google’s personalised advertising policy states that negative lists may be used to exclude people for any reason, though they must not be used for positive personalisation.
Frequency: how often is too often?
Frequency is how many times one person sees your ads in a period. Platforms generally allow caps. Google Ads help material describes frequency capping as a way to limit the number of times a person is exposed to an ad per day. There is no universal ideal number, so begin conservatively and look at the trend. Warning signs include falling click rates over time, rising negative feedback and visits that never convert.
Rotate your creative too. Showing the same banner for weeks is the quickest way to create fatigue. Use different angles: a benefit, a proof point, an answer to a common objection, a clear offer.
What to show
Retargeting messages should continue the conversation, not restart it. Link back to a page built for returning visitors, such as a comparison, a testimonial page you are entitled to use, or a simple enquiry page. See our guide on landing pages that convert campaign traffic for page design.
Privacy and policy considerations
Retargeting depends on collecting data about visitors, so it carries obligations.
Platform policy
Google’s personalised advertising policy says advertiser-curated audiences, such as Customer Match, data segments, lookalikes and audience expansion, cannot be used when promoting sensitive interest categories. It also says users under 18 are not eligible for personalised advertising, that ads must not collect or contain personally identifiable information except in Google-provided formats, and that advertisers should include data segment information in their privacy policy. Other platforms have their own rules, so read each one.
Australian privacy law
In Australia, the Privacy Act and the Australian Privacy Principles govern collection and use of personal information. The Office of the Australian Information Commissioner (OAIC) has published guidance on third-party tracking pixels and privacy obligations. Read that guidance on the OAIC website, along with the Privacy Act, before launching. In general terms, expect to need a clear privacy policy that describes the tools you use, a notice at or near the point of collection, extra care with sensitive information (health is an obvious example), and an easy way for people to opt out of tracking-based advertising. This is general information, not legal advice.
Practical safeguards
- Describe your tags, audiences and advertising partners in your privacy policy.
- Use a consent mechanism that is accurate about what happens when people accept or decline.
- Do not build audiences from pages that reveal health, financial hardship or other sensitive circumstances.
- Keep audiences from becoming so small that individuals could be singled out.
- Review which pixels are installed. Remove old ones.
- Honour opt-outs and update lists accordingly.
Measuring retargeting honestly
Retargeting audiences are people who were already interested, so many would have returned anyway. A last-click report will therefore flatter it. Where you can, hold back a small group from seeing ads and compare conversion rates, or at least compare against a prior period. Our article on measuring creative campaign performance covers how to set expectations and metrics up front. For where paid reminders fit alongside unpaid channels, see organic social vs paid advertising.
A starter plan
- Confirm your privacy policy and consent flow are accurate.
- Create two or three intent-based audiences with sensible windows.
- Exclude converters.
- Set frequency limits and prepare three or four creative variations.
- Review after a few weeks and trim or extend windows based on results.
Where Radiance Impact fits
Radiance Impact’s Growth division plans campaigns and paid social, and can help structure audiences and creative. To discuss a retargeting plan, contact us or see the Growth page.
Sources
- How your data segments work, Google Ads Help
- Personalized advertising policy, Google Advertising Policies Help
