The quality of a lookalike depends on its source. A list of everyone who filled a form copies the habits of form-fillers; a list of people who completed a site visit or booked copies the habits of buyers. Meta sets a minimum source size and publishes its current recommendation in its help centre; smaller brokers often pool visit-completed leads across several months to reach a usable list.
Lookalikes are set as a percentage of a country’s users — a 1% lookalike in India is the closest match, a 5% one is broader. For property, combine the lookalike with location targeting near the project or the localities you serve. The source list is personal data, so the same DPDP consent and privacy-notice rules apply as for retargeting.
Example
Choosing the source (illustrative)
An Ahmedabad builder tests two lookalikes for the same ad: one built from 3,000 form-fillers, one from 600 people who completed a site visit. Over a month (illustrative), the second gets fewer leads but more of them book visits, so the builder keeps the visit-based source and refreshes it monthly.
Figures are illustrative, not market rates.
Questions about Lookalike audience
How big should the source list be?
Check Meta’s current minimum and recommended source size in its Ads Help Centre when you build the audience. Quality matters more than size: a few hundred real buyers make a better source than thousands of casual form-fillers.
What is the difference between a lookalike and retargeting?
Retargeting reaches the same people who already interacted with you. A lookalike reaches new people who resemble them. Teams usually run both: lookalikes to find new buyers, retargeting to bring back those who showed interest.
Sources
Reviewed