What is a lookalike audience?
Targeting by interests guesses who might buy. A lookalike audience starts from people who already did something valuable and asks the platform to find more people like them.
How a lookalike audience is built
In Meta Ads a lookalike starts from a custom audience, a list of people you already know: a customer list, website visitors recorded by the Meta pixel, people who opened or sent a lead form, or people who engaged with your page. You pick one or more countries and a size, and Meta builds a new audience of similar users that excludes the source itself.
Size is a percentage of the population of the chosen countries, usually 1 to 10 percent. A 1 percent lookalike is the closest match and the smallest; 10 percent reaches more people who are less similar. Meta requires a minimum number of source people from one country and suggests that a source in the thousands works better than a few hundred. Rules change, so check the current Meta documentation.
What makes a good source
- People who did what you want more of: paying customers beat everyone who ever clicked.
- A clean list without test entries, staff and disqualified leads.
- One pattern: mixing buyers of very different products blurs the signal.
- A lawful basis, such as consent, for uploading a customer list. In the EU this falls under the GDPR, so check with whoever handles data protection in your company.
A small example (illustrative numbers)
A furniture shop has 4,000 leads from lead forms, of which 600 became paying customers. A lookalike built from all 4,000 finds people who like filling in forms. One built from the 600 customers finds people who resemble buyers: a smaller source, but usually the better start for a campaign that aims at sales.
Limits worth knowing
In newer Meta setups such as the Advantage+ audience, your audience choices may act as suggestions rather than strict limits. Special ad categories, such as housing, employment or credit, have tighter targeting rules. And a lookalike ages: without a refreshed source, it keeps looking for people like last year's customers.
Lookalikes in OrgLines
OrgLines shows the Custom and Lookalike audiences of each connected Meta ad account and flags audiences too small to use. The campaign wizard offers the Advantage+ audience or your own targeting. Because Meta lead form leads land in the Lead Center next to the campaign data, you can see which leads were qualified and became orders, which is exactly the list you want as a source.