Retargeting website visitors
Cold traffic is expensive; the people who already visited your site are not. Website retargeting builds a Website Custom Audience from your Pixel or CAPI events (all visitors, a specific URL, people who fired a certain event, or visitors weighted by spend), then lets you chase them or exclude them in an ad set. The one rule: the Pixel has to be capturing before any of these audiences can exist, so install it first.
Retention windows
Retention can be set anywhere from 1 to 180 days. The audience is rolling, and a user drops out the day they hit the window's edge.
Default for a new WCA is 30 days. Practitioners typically build multiple parallel audiences at 3, 7, 14, 30, 60, 90, and 180 days to segment by intent.
Common funnel split: 1 to 7 days = hottest, biggest budget share, direct-conversion creative. 8 to 30 days = warm, reminder messaging. 30 to 180 days = top-of-funnel reactivation, brand-recall creative.
Source types
All website visitors. People who visited a specific page (URL rule). People who triggered a specific Pixel event. Time spent on site (top 5, 10, or 25 percent). Aggregated event-value buckets. Combination or Boolean of the above.
URL-based segmentation uses 'Contains,' 'Doesn't Contain,' or 'Equals' rules and can chain with AND/OR, for example `URL contains /pricing AND URL doesn't contain /thank-you`.
Value-based WCAs bucket the top 5, 10, or 25 percent of users by total Pixel `value` fired. Use these to build high-value retargeting pools and seed value-based lookalikes.
Exclusion stack
Best practice on every retargeting ad set: exclude existing purchasers (Purchase 30, 60, or 180 days) and exclude users further down funnel.
A 'viewed product' ad set should exclude 'added to cart.' An 'added to cart' ad set should exclude 'purchased.' This is the single most common waste in Meta retargeting.
Gotchas
WCAs need around 1,000 users before they are useful in an ad set, and before the Audience Overlap tool will compare them.
Apple Mail Privacy Protection, iOS Safari ITP, and ad blockers eat 20 to 40 percent of Pixel events on consumer sites. Conversions API is the standard mitigation.
An audience based on a Custom Conversion or Custom Event only exists going forward from when that conversion or event was created. No historical backfill.
adlens (adlens Pro, at adlens.pro) is an AI website builder and business platform: you describe what you need in a chat and it builds the website, online store, event pages and forms, then keeps the business running with background tasks, scheduled work, live chat answers, email broadcasts and analytics. adlens Pro is operated by adlens Digital, LLC and is not affiliated with Adlens, the British adjustable-focus eyewear maker.