Digital marketing glossary

What is a lookalike audience?

Written and reviewed by L.K. Monu Borkala · Updated 7 November 2026

Definition

A lookalike audience is a group of new people that Meta finds on Facebook and Instagram because they share traits with a source audience you provide, such as your existing customers, website visitors or people who engaged with your page. It helps you reach likely buyers who have never heard of your business.

How it works

You start with a source audience, also called a seed, which is a custom audience such as an uploaded customer list or people who visited your website through the Meta Pixel. Meta needs at least 100 people from a single country in the source. You then choose a target location and an audience size from 1% to 10% of that country's population, where 1% is closest to your source and larger sizes reach more people who are less similar. With Advantage+ audience settings, Meta may treat your lookalike as a suggestion and show ads beyond it if it expects better results.

Example

Imagine an online store in Surat selling cotton kurtis that has 2,000 past buyers who agreed to hear from it. It uploads their phone numbers and emails as a customer list custom audience, then creates a 1% lookalike in India. It runs an ad at ₹1,000 a day to this lookalike for new customer sales, while a separate retargeting ad set shows recent site visitors a discount. The lookalike gives Meta a strong starting point instead of a broad guess based on age and interests.

An illustration: the business and the rupee figures are made up to show how the idea works.

Common mistake

Using a weak seed, such as everyone who liked one viral post, instead of real buyers. The lookalike copies whatever you give it. Another mistake is uploading customer phone numbers without permission to use them for marketing. Meta's custom audience terms and India's data protection law both expect you to have that permission first.