Glossary · Paid mediaTOFU
Lookalike audience
The short answer
A lookalike audience is a group of people an ad platform identifies as similar to a "seed" list you provide — usually your customers. Upload your best buyers, and the platform finds more people who share their characteristics and behaviours.
The quality of the seed decides the quality of the lookalike. A list of your highest-value repeat customers produces a very different audience from a list of everyone who ever visited your site.
Best seeds, roughly in order
- High-LTV customers — repeat buyers or top spenders
- All purchasers from the last 180 days
- Qualified leads or customers from your CRM, for lead-gen businesses
- High-intent site visitors — added to cart, started checkout
- Engaged video viewers — for top-of-funnel reach
Lookalikes in the Advantage+ era
Meta increasingly treats audiences as suggestions and expands beyond them when it finds better performance. Lookalikes are still useful as signals, but creative and conversion data now carry more of the targeting weight.
Seed list quality ranking
- Highest-LTV customers
- Repeat purchasers
- All purchasers
- Qualified leads
- Engaged visitors
Upload customer lists only with consent and hashing, through official tools.
Lookalike audiences in practice
A brand uploads its best customers, and Meta builds an audience of similar people for prospecting. With strong creative, the lookalike finds buyers more efficiently than broad interests.
Lookalike tips
- Use high-value customer lists as sources
- Refresh source lists regularly
- Test against broad targeting
Common lookalike mistakes
- Using low-quality source audiences
- Never refreshing source lists
- Overlapping lookalikes competing with each other
Frequently asked questions
How big should a seed list be?
Larger seeds give the algorithm more to learn from; platforms typically require a minimum of a few hundred matched people, but a few thousand good customers work much better.
Do lookalikes work on Google?
Google uses customer lists and similar signals within Demand Gen and Performance Max, though its mechanisms differ from Meta's.
What size should a lookalike be?
Smaller percentages are closer to the seed; larger ones add reach. Test sizes against your goals.
Does Google have lookalikes?
Google offers similar segment options in some campaign types, such as lookalike segments in Demand Gen.
Are lookalikes still useful with Advantage+?
They can be, but broad targeting with good signals often performs as well or better.
What size lookalike should we start with?
Smaller percentages are closer matches; larger ones reach more people.
Related terms
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