Lookalike Percentage Tiers

Paid Media

Also: Lookalike Audience Size · LAL Percentage

The tradeoffSimilarity versus reach

1 percent tierClosest match, smallest pool

10 percent tierBroadest reach, loosest match

Watch forSource audience quality decides everything

Quick definition

Lookalike percentage tiers are the size settings platforms like Meta offer when building a lookalike audience, usually ranging from 1 percent to 10 percent of a country's population. A lower percentage matches people more closely to your source audience. A higher percentage trades precision for reach.

How it varies across Australia

Australian advertisers often exhaust tight lookalike tiers faster than advertisers in larger markets because the eligible population is smaller. Businesses running national campaigns tend to stack multiple tiers earlier than they would in the United States or United Kingdom.

Explore acquisition benchmarks across Australian industries →

What it actually means

Lookalike percentage tiers control one thing: how far the platform is willing to stretch before it stops calling someone similar to your source audience. A 1 percent tier only includes people the algorithm considers extremely close matches. A 10 percent tier widens that net considerably, trading precision for scale.

The tiers matter less than what feeds them. A lookalike audience built from a weak custom audience, say, a list of one-time discount hunters, will find more people like discount hunters no matter which percentage you choose. Tier selection can't fix a bad source.

Most advertisers treat 1 percent as the default because it sounds like quality. In practice it often means a tiny, quickly-exhausted pool that drives your cost per acquisition (CPA) up once frequency saturates. Retargeting audiences and custom audiences built from actual purchasers usually make better lookalike seeds than broad site-visitor lists.

Think of segmentation as choosing the right ingredients, and the percentage tier as choosing how much you're willing to dilute the recipe before it stops tasting like the original.

A 1 percent lookalike isn't automatically better. It's just narrower. Whether narrower helps depends entirely on what you fed it.

How it shows up

You'll see percentage tiers as a slider or dropdown when building a lookalike audience in Meta Ads Manager, typically from 1 percent up to 10 percent per country. The setting shows up again later in your reporting as reach and frequency. Tight tiers plateau fast, frequency climbs, and click-through rate (CTR) starts dropping as the same small pool sees your ad repeatedly. Wider tiers sustain reach longer but dilute relevance, often visible as a slower but steadier decline in conversion rate rather than a sharp frequency spike.

The Australian context

Australia's smaller population means lookalike pools shrink faster than equivalent tiers in bigger markets. A 1 percent lookalike in Australia might represent a genuinely small number of eligible people once you overlay age, location and platform activity filters. Advertisers running national campaigns often need to combine several percentage tiers, or layer lookalikes with interest-based audience targeting, to maintain enough reach for stable delivery across a full quarter.

Where people get this wrong

Assuming 1 percent always outperforms wider tiers.Narrow tiers exhaust quickly, especially in smaller markets. Once frequency climbs too high, cost per acquisition rises regardless of how tight the match started out.

Building lookalikes from weak or generic source audiences.The algorithm can only find more people who resemble the seed. A source list of low-intent visitors produces a lookalike full of other low-intent visitors, no matter the percentage.

Never refreshing the source audience.Customer behaviour changes and old purchaser lists go stale. A lookalike built from twelve-month-old data can drift away from who your current best customers actually are.

Lookalike Percentage Tiers vs Custom Audience

	Lookalike Percentage Tiers	Custom Audience
What it targets	People similar to an existing list	People already on your existing list
Reach	New, previously unreached people	Limited to who you upload or pixel-track
Depends on	Quality of the source audience	Size and recency of your own data
Best used for	Prospecting and top-of-funnel scale	Retargeting and retention

Common questions

What percentage should I start with for a lookalike audience?

There's no universal answer. A 1 percent tier gives the closest match but exhausts fast in smaller markets like Australia. Many advertisers start around 2 to 3 percent to balance similarity with enough reach to sustain delivery for a few weeks.

Does a smaller percentage always mean better performance?

No. Performance depends more on the quality of the source audience than the percentage chosen. A tight tier built from a weak list can underperform a wider tier built from your best customers.

Can I combine multiple lookalike percentage tiers?

Yes. Many advertisers stack a 1 to 3 percent tier with a 4 to 6 percent tier as a separate ad set to extend reach once the tighter tier saturates, especially useful in smaller markets where tight tiers exhaust quickly.

How often should I refresh the source audience?

Refresh whenever your customer profile shifts meaningfully, or at minimum every few months. Stale source data drifts away from who is currently converting, which weakens every percentage tier built from it.

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About New Rebellion

New Rebellion is a marketing intelligence consultancy. We build tools, score Australian businesses on how their marketing actually performs, and publish Debrief every day. This dictionary is part of how we work in the open.

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