Lookalike audience

A lookalike audience is a group of new people Meta finds because they resemble a source audience you give it, usually your existing customers. Meta looks at traits like demographics, interests and behaviors in the source and delivers your ad to people who share them. You choose how close the match is with a percentage: smaller means closer, larger means broader.

How does Meta define a lookalike audience?

From Meta's About lookalike audiences:

A lookalike audience is a way your ads can reach new people who are likely to be interested in your business because they share similar characteristics to your existing customers.

To build one, Meta says "our system leverages information such as demographics, interests and behaviors from your source audience to find new people who share similar qualities." The source audience is "the audience a lookalike audience is based on", for example your Page fans.

How big should the source audience be?

Meta's Create a lookalike audience page gives the numbers:

Size is not everything. Meta adds that "the quality of your audience also matters", and that you "may get better results depending on your goals if you use an audience made from your best customers rather than one that includes all your customers." Its value-based lookalike option builds the source from a custom audience that carries customer value.

Does a lookalike still have a location?

Not on its own any more. Meta's create page says: "You no longer select audience location when creating a lookalike." Instead, "We'll use the ad set's location settings to find people similar to your source audience", and the estimated size shows only once the lookalike is in an ad set. Existing lookalikes are not affected. A new one shows Populating first, which "can take up to 3 days", though you can start running ads with it right away.

Will Meta deliver outside my lookalike?

It can. Meta's About Advantage+ lookalike page says the setting lets the system "deliver ads to people outside your defined lookalike audience if it's likely to improve performance", and that it "is automatically enabled for new, duplicated and draft campaigns and ad sets using lookalike audiences created from mobile, website or customer list custom audiences." With Advantage+ audience on, a lookalike is a suggestion rather than a boundary, unless you make it a control. Meta's create page lists "custom audiences and lookalike audiences" among the audience controls under Further limit your audience, adding: "You may have to uncheck the Use as a suggestion boxes."

What it means for your ads

• Feed it your best customers. Meta's own advice is quality over the whole list, so a source of repeat buyers beats a source of every email you have.
• Expect broad delivery. With Advantage+ lookalike on by default, the percentage you pick is a starting point. The ad has to work for people beyond your closest match.
• Use several at once if you need to. Meta says you can use "multiple lookalike audiences at the same time for a single ad set", and the ad set then reaches people in any of them.

Common mistakes

• Assuming the percentage is a hard limit. It is one only if Advantage+ lookalike is off and the lookalike isn't a suggestion: either Advantage+ audience is off, or you unchecked Use as a suggestion.
• Ignoring the restrictions. Meta says lookalikes "are limited or unavailable for some ads about financial products and services, employment or housing opportunities", and targeting is limited for audiences that include people under 18 (or older in some countries).

Sources

• About lookalike audiences — Meta Business Help Center: the definition, how it's built, the percentage and source quality (rendered in a browser, accessed 2026-10-18)
• Create a lookalike audience — Meta Business Help Center: source size, the 500 limit, exclusion, location and status (rendered in a browser, accessed 2026-10-18)
• Source audience — Meta Business Help Center: the source audience definition (rendered in a browser, accessed 2026-10-18)
• Create a value-based lookalike audience — Meta Business Help Center: building from a custom audience with customer value (rendered in a browser, accessed 2026-10-18)
• About Advantage+ lookalike — Meta Business Help Center: delivery outside the lookalike and the default (rendered in a browser, accessed 2026-10-18)
• How to create a campaign using Advantage+ audience — Meta Business Help Center: lookalikes as audience controls and the Use as a suggestion box (rendered in a browser, accessed 2026-10-18)

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Meta's help pages are client-rendered and show no date; they were read in a real browser on 18 October 2026. Meta revises them without notice, so check the source before acting on any of it.

Terrads makes a batch of different ads in one go, so a broad audience gets several angles to respond to instead of one.