How to Retarget Website Visitors on Meta

Advertiser method. Meta does not publish this as a rule. The mechanics below come from Meta’s documentation; the method itself is common advertiser practice, and results vary.

Retarget website visitors when your site already gets enough traffic to fill an audience and you have an action you want visitors to finish, such as a purchase. Meta’s own example is people who visited in the last 30 days but haven’t converted yet. It fits poorly when few people visit, because the audience stays small and starts filling only from the day you create it.

Which visitors can you retarget?

Meta lets you build a website custom audience from several rules, each with its own lookback:

Rule	Who it captures
All website visitors	Everyone who visits pages carrying your pixel
People who visited specific web pages	Visitors to URLs that contain, don’t contain or equal what you enter
Visitors by time spent	The top percentile of visitors by time on your site
Meta Pixel events	People who fired a standard or custom event, such as add to cart

Which rule to use is your call. You can split visitors by how far they got, for example product viewers and cart adders, so each group sees a different message. That is practice, not a Meta rule.

How long should the window be?

Meta says each rule goes back a number of days you choose, up to 180, or up to 2 years for purchase events. Its example for retargeting uses 30 days. Beyond that, the Meta pages cited here give no recommended number.

The trade-off is yours to weigh. A short window keeps the audience to recent visitors and makes it smaller. A long window makes it larger and includes people whose visit was long ago. Meta says the audience refreshes constantly: people drop out when the window passes, and new visitors are added.

How do you keep buyers out?

Each rule section in a website audience can include or exclude people, and you can combine up to 5 sections as long as at least one includes people. A reading of that rule: “added to cart, not purchased” is an include section for the cart event plus an exclude section for the purchase event. For catalog campaigns, Meta recommends including people who viewed or added products to their cart and excluding people who purchased.

What has to be in place first?

Your Meta Pixel must be active. The audience starts populating from the time you create it and does not backfill, and it has to populate before you can use it. Meta also says the audience may be smaller because it may not include events from some iOS 14 users. Targeting options are limited for audiences that include people under 18.

How can you decide for your own site?

Pick the action you want finished, then choose the visitors who started but did not finish it.
Choose a window you can defend, and start with a number close to your normal buying cycle. That is method, not a Meta rule.
Add an exclude section for people who completed the action.
Check the audience status and estimated size before you attach it to an ad set.

FAQ

How many days should a retargeting window be?

Meta states the maximum, 180 days or 2 years for purchases, and uses 30 days in its retargeting example. It gives no recommended number on the pages cited here. You can match the window to how long your buyers take to decide.

Will my audience include people who visited before I made it?

No. Meta says a website custom audience starts populating from the time you create it and won’t backfill. A new audience can look empty or small at first, and Meta says it has to populate before you can use it.

Do I need to exclude people who already bought?

Meta’s recommended catalog setup excludes people who purchased, and website audience rules let you exclude them. Without that rule, buyers who still match your include rule may keep seeing the ads. Whether that suits you, for example for a repeat purchase, is your decision.