A custom audience is a Meta ad audience built from your own data (website visitors, a customer list, app or offline activity) or from people who engaged with your content on Facebook, Instagram, WhatsApp or Threads (Meta Business Help Center). Advertisers use them to retarget, to keep existing customers out of prospecting, and as the source of a lookalike audience. An ad account can hold up to 500.
Custom audience sources
| Source | Built from | A lead gen use (example) |
|---|---|---|
| Website | visitors tracked by the Meta Pixel | landing page visitors who didn’t submit |
| Customer list | emails, phone numbers and other identifiers you upload | exclude leads you already have; seed a lookalike |
| Lead form | people who opened or submitted your lead forms | retarget people who opened an instant form |
| Other engagement | video, Instagram account, Facebook Page, events, Instant Experience, shopping, Marketplace listings | warm prospecting |
| App activity, catalog, offline activity | app actions, catalog items, in-store or other offline interactions | rarely relevant to lead gen |
Meta also offers an exclusion-only custom audience: a customer list you can only use to exclude people.
How Meta builds each type
- Website. The Meta Pixel has to be active. You set rules on events or URLs (up to five per audience) and a retention period in days. The audience fills from the day you create it, with no backfill, and Meta warns it may miss events from some iOS 14 users (create a website custom audience).
- Customer list. Meta hashes your identifiers before use and matches them against profiles. More identifiers mean a better match rate, and Meta says it learns no new identifying information from the hashed data (customer lists). Audience Manager shows a match score out of ten and marks a list Outdated after 30 days without an update (use custom audiences).
- Engagement. A rolling window: pick 30 days and someone who engaged 29 days ago is in today, and out tomorrow unless they engage again (engagement audiences).
Where you see it in Ads Manager
Create and check audiences under Audiences (Create audience, then Custom audience); each one shows Populating until it’s Ready. In a Leads campaign’s ad set, an audience added under Add suggestions is a suggestion that Meta may deliver beyond, which Meta calls Advantage+ custom audience. To make it a hard limit, choose Further limit the reach of your ads and uncheck Use as a suggestion. Exclusions are always hard limits (audience settings); the Advantage+ audience entry has the full split.
Restrictions on certain custom audiences
Meta flags custom and lookalike audiences that include information its terms don’t allow, such as a specific health condition (its example: arthritis) or financial status (credit score). A flagged audience can’t be used in new campaigns, and live campaigns using one should be edited or paused (Meta Business Help Center). Remove the information, build a new audience, or request a review.
The data behind an audience can be restricted too. Meta may assign your data sources to categories such as health and wellness or financial service (data source categories). Some categories bring core setup, which strips custom parameters and everything in a URL after the domain, so audiences whose rules depend on them can populate slowly or stop updating (core setup). A “visited /thank-you” audience is exactly that kind. The Meta dataset entry covers where these categories live.
A custom audience changes who sees the ad; whether it lowered your cost per lead shows up in the leads. DropCPL computes CPL per creative and per landing page from first-party leads and spend synced per ad from the Meta Ads API. Start free →
Custom audiences in lead generation
The most useful custom audience in lead gen is often an exclusion. Upload the leads you already have as a customer list and exclude them from prospecting, so you stop paying to collect the same person twice. Excluding a custom audience doesn’t switch Advantage+ off, Meta says (what turns Advantage+ on and off).
For retargeting landing page visitors, make the website audience a hard control: Meta itself doesn’t recommend Advantage+ audience for retargeting. And if your landing page leads reach your CRM through DropCPL’s webhooks, that CRM is where your customer list comes from.
Related terms
- Lookalike audience: new people similar to a custom audience
- Advantage+ audience: where inclusions turn into suggestions
- Meta dataset: where the Pixel events behind website audiences arrive
- Instant form: the source of lead form audiences