Learn

Your Meta lookalike needs 100 people from one country

Meta requires at least 100 people from a single country in the source audience. A list spread across five markets can fail while looking big enough.

Meta states that a lookalike source audience needs at least 100 people from one country. The country part is what surprises people.

A 300-person customer list sounds comfortably over the line. Spread it across the UK, Ireland, Germany, France and Spain at 60 apiece and no single country clears 100, so there's nothing to build from.

Bigger seeds aren't automatically better

A lookalike is only as good as what it's modelled on. Seeding from everyone who ever bought gives you a model of your average customer, including the ones who refunded. Seeding from your best 200 customers usually beats seeding from all 5,000, and it's the version most people never try.

The proxy-discrimination trap

If the campaign is about housing, employment or credit, a lookalike seeded on a skewed customer list can reproduce a protected-characteristic exclusion without anyone choosing one. The declaration doesn't save you from that, because the test is the effect and not the intent. Our note on special ad categories covers the rest.

See the Meta ad specs, quoted with sources.