Someone ordered sneakers from you, paid, and is waiting for the parcel. The next day they open the news and there are your sneakers again, now with a discount. A week later the same sneakers show up on a website in a video. It annoys the customer, and you pay for every one of those views.
Most often this is not a mistake but ordinary remarketing at work. Remarketing (repeat ads for people who have already visited your site) does not know a person has bought until someone tells it. Below: what exactly to tell it, for how many days, and what to check in your own account.
A note on limits. The specific periods (“7–14 days”) come from practitioners and one of our knowledge bases, not from Google’s help: we found no such period in Google’s help. Anything presented as practice is labeled so. We checked the Google Ads menus against Google’s help on November 5, 2026, but could not open Meta’s help on audience exclusions in full, so we do not give Meta menu names.
How a buyer ends up under your own ad
Remarketing works through a list: your site has a tag (a small piece of code that remembers a visitor), and everyone who visits joins the audience. A buyer also visited the site, so they are on the list. If a campaign is set to “all visitors”, it shows to those who have already paid too.
This hits the wallet twice. First, you pay for impressions and clicks on someone who needs nothing right now. Second, they see an ad for the same product and think they are being watched or that the ads were set up carelessly. The sources we checked have no numbers on how much this reduces repeat purchases, so we give none.
For how many days to exclude: practice versus Google’s help
Here is what practitioners say. People who bought recently are advised to be removed from remarketing for 7–14 days. For cosmetics, about two weeks is mentioned: that is how long a person uses a product before needing a new one. For travel and expensive purchases (furniture, appliances, renovation) they are removed for months, because the person will not buy again soon. This is a retelling of practitioners (one of their databases, no primary source), not a Google rule, and we present it that way.
What Google Ads help says. Audience segments can be excluded in Search, Display, Demand Gen, Standard Shopping, Video and Performance Max campaigns. But the help advises something different: first look at how segments perform, and only then exclude anything. It gives no periods at all. So there are two approaches, and both make sense. Some say: remove buyers right away, it almost always saves money. Google’s help is more careful: look at results rather than cutting blindly. In our experience: customers who have already paid are best removed straight away, while other groups, for example people who looked at a product for a long time, should be observed first.
When not to exclude
Practitioners differ here too, and it is useful to know. If you sell something bought once and for a long time (a sofa, a renovation, sneakers), the person is worth removing from the list for longer. If the product is consumable (pet food, cosmetics, tea, spare parts), the person will buy again and the ad may be useful to them.
For upselling, there is no need to remove the person at all: the goal is precisely to bring them back with a new purchase. The advice is not to cross them out but to run a separate campaign or group with complementary products or a refill reminder. For things that wear out (sneakers), a reminder after about six months is mentioned. For services with renewal, the reference point is different: the date of the previous deal. All of this is practice, but the logic is simple: we do not show the same thing, but related items are fine.
Where it is in Google Ads
According to Google’s help, in Google Ads it works like this: in the account, go to “Audiences” in the “Campaigns” menu. The “Exclusions” module lists excluded segments. To add one, select “Edit exclusions”, in the “Exclude from” drop-down choose “Campaign” or “Ad group”, tick the segments and save with “Save audience segment exclusions”.
There are two traps. First: you cannot exclude an audience while creating a campaign; it is done in an already created one. Second: the segment itself must exist. It is built from a tag on the site (the “thank you for your order” page) or from a customer list from your CRM. In the customer-list help, the path leads through the tools, the shared library and the audience manager. Membership duration in such a segment cannot exceed 540 days, and for the segment to stay valid at least 100 members must be added or changed within the last 540 days. That help has no separate item “exclude customers from the list”: exclusion goes through the audience segment.
There is also a nuance with “how many days”. In Google’s help we did not find a “exclude for 10 days” setting as a separate button. How it is done in practice (membership duration in a segment, separate segments by days) is best clarified with your contractor: this is the part you cannot check by eye.
And in Meta?
The same applies to Facebook and Instagram ads: your own customers can be removed from ad sets that target site visitors. From Meta’s help we saw only an excerpt about dynamic product ads: it has a setting that limits showing ads to people who purchased within a set number of days. We could not open the page in full, so we do not give the exact option name. Look in the ad set for the “Audience” block and the option to remove people from your own lists. Also, according to retellings, Meta has changed the label of this block, and for Advantage+ campaigns sources disagree: some write that ad-set-level exclusions are unavailable there, others that they are set at account level. We wrote about how Meta works with a warm audience in the article “Discount for a Cold Audience Does Not Work”: there it is only one line.
What to ask your contractor and what to look at yourself
Setting this up yourself is hard: you need access to the lists in the account. But checking whether it exists is quick.
- Ask the contractor to open “Audiences” → “Exclusions” and show whether there is a segment of people who bought.
- Ask in one sentence: are buyers excluded from remarketing, and for how many days?
- Ask whether customers were also removed where you run a separate upsell ad.
- If the answer is “we don’t know” or “it happens by itself”, that is already an answer.
The “buy from yourself and look” test does not work here: you constantly visit your own site, so the ad chases you for any reason. What helps instead: ask an acquaintance to order something from you and ask a day or two later whether they see your ad.
What to check
- Is there a segment of people who bought in the account (from a tag on the “thank you for your order” page or from a CRM list)?
- Is it removed from all remarketing campaigns, not just one?
- Does the period fit the product: a week or two for ordinary ones, longer for expensive ones?
- Has the ad not disappeared where you need an upsell?
- Is this list updated, not uploaded once and forgotten?
Separately, on a similar problem: when an ad promises a promo that has already ended, we wrote about it in “The Promo Is Over, but the Ad Still Promises It”. And for people who abandon their cart, who are exactly the ones remarketing is for, see the article on abandoned carts.
Summary
Remarketing does not know someone bought until it is told. Three things:
- remove people who bought from remarketing for a period that fits your product (a week or two, longer for expensive purchases);
- for upselling consumable products there is no need to remove them, a separate ad is better;
- ask your contractor: are buyers excluded from remarketing, and for how many days?
How we work with advertising for shops and services, see the sections on search ads and Performance Max.
Want a free audit of your Google Ads account? Send us a request: we will look at your account and tell you whether your ad is chasing people who have already bought.