A Reddit ad group can have “retargeting” in its name without being limited to people who already know your business.
Before increasing its budget, I would check one thing: is automated targeting allowed to expand beyond the custom audience?
That setting changes the question the campaign can answer. Reaching previous visitors and finding additional people who might convert can both be useful. But they are not the same job, and I would not report them as if they were.
A selected audience is not always a boundary
Reddit’s automated targeting overview describes a system that can reach beyond manual selections. It uses targeting inputs as signals rather than treating every selection as a fixed requirement.
Its audience-targeting documentation is more specific about custom audiences: when automated targeting is enabled for eligible users, custom audiences combine with other Reddit audience targeting through an OR relationship. People in the custom audience and additional people predicted to perform may see the ads.
So adding a website audience does not, by itself, prove that every impression went to a previous website visitor.
Expansion is not automatically a problem. The problem is judging its results against a narrower assignment than the settings actually enforce.
Define what you mean by retargeting
Reddit’s custom-audience guide distinguishes website retargeting, customer lists, lookalikes, and engagement retargeting. Those starting points represent different relationships with your business.
I would write the intended audience in plain language before opening the settings. For example: “People who visited the product page recently but have not signed up.” That is more useful than “warm audience.”
Then check whether the actual audience definition matches that sentence. Which event supplies the audience? What is the lookback window? Is the event firing on the action you think it represents?
A page visit tells you that someone reached a page. It does not confirm that they understood the product or are ready for a sales conversation. The follow-up should still explain why the next step is useful.
Audit the saved settings, not the campaign name
Here is the short review I would use before calling an ad group retargeting:
- Included audience: record the exact audience and the behavior or list that defines it.
- Recency: check the lookback window rather than assuming it matches the name.
- Expansion: check whether automated targeting is enabled and what the selected campaign setup allows you to control.
- Other targeting: review how communities, interests, or keywords combine with the custom audience.
- Exclusions: check whether people who already completed the intended action should be excluded, and whether the relevant audience is configured correctly.
- Measurement: record the optimization event, attribution settings, and the downstream action you will review.
For a test intended to stay within a defined audience, use a configuration that supports that restriction and confirm expansion is off. If the available setup does not let you enforce it, do not label the test audience-only retargeting.
Reddit also supports custom audiences as exclusions, as described in its custom targeting overview. I would check exclusions separately from inclusions. Adding an audience to target is not the same action as excluding existing customers.
Test expansion as its own decision
My starting point would be a focused comparison, not a rebuild of the whole account.
Hypothetical example: a software business wants to promote a product walkthrough to previous website visitors. The team is deciding whether broader delivery is worth funding. This is an illustrative setup, not a client result.
The first version uses the intended website audience with expansion disabled, where the campaign controls support it. The second uses the same starting audience with automated targeting enabled. Keep the offer, creative, landing page, optimization event, and measurement window consistent so fewer things change at once.
Name them clearly, such as “Website audience | restricted” and “Website audience | expansion enabled.” Record the settings and the date the comparison starts.
The expanded version can still include the original audience, so these are not automatically two mutually exclusive groups. Two ad groups running together are also not automatically a randomized experiment. If there is no suitable controlled test available, treat the comparison as directional. Differences in delivery, overlap, and small samples can limit the conclusion.
If the budget cannot support both versions meaningfully, I would avoid splitting it into two tiny tests. Choose the question that matters first, then revisit expansion when there is enough activity to evaluate it.
Match the message to the audience you can actually reach
A follow-up ad can be more direct, but it should not depend on everyone remembering an earlier interaction.
In the hypothetical walkthrough example, “See how the approval process works” explains the offer to both a previous visitor and someone seeing the business for the first time. “Ready to finish where you left off?” assumes a history the expanded audience may not have.
I would start with one clear message that makes sense across both setups. If you change the audience settings and the creative together, you will have a harder time knowing which change mattered.
Separate delivery, conversion credit, and business value
More reach tells you the campaign delivered more broadly. A lower reported cost per conversion tells you something about the measured event. Neither tells you, on its own, that you acquired more qualified customers.
I would review spend, the intended website action, lead or signup quality, and downstream activity. Keep attribution settings consistent and check the click-through and view-through conversion split before comparing results.
Unless your reporting separately identifies original-audience and expanded-audience outcomes, treat the expansion-enabled result as blended. Do not assign all of its conversions to previous visitors, or assume all of them came from new people.
If expansion produces useful outcomes at an acceptable cost, that can be a reason to continue. If it only improves a shallow event while lead quality declines, review the event and offer before adding budget.
The practical takeaway is simple: make the audience definition, campaign settings, and reporting label agree. Then decide whether the next dollar should go toward a follow-up or a broader acquisition test.
Official Reddit documentation checked October 20, 2026. Controls and availability can vary by campaign setup; confirm the saved settings in your account before launching.