Meta Lookalike Audiences use machine learning to find users who have similar characteristics and behaviours to a seed audience you provide. When built from the right seed audience — your highest-value customers, most engaged buyers, or best-matched leads — Lookalike Audiences consistently outperform interest-based or demographic targeting for most ecommerce stores.
How Lookalike Audiences Work
You provide Meta with a source audience (at least 100 people, ideally 1,000+). Meta analyses the characteristics of that source audience across hundreds of signals: demographics, interests, behaviour, app usage, video viewing history, purchase patterns on Meta’s network. Meta then finds new users in your target country who most closely match those signals.
The percentage you choose (1%, 2%, 5%, 10%) determines how strictly Meta matches:
- 1%: the top 1% of your target country’s users most similar to your seed audience. Smallest, most precise.
- 2–5%: broader match, larger audience.
- 10%: looser match, largest audience, least precise.
The Best Seed Audiences for Shopify Stores
Seed 1: All-Time Customer List (Best Start)
Upload your entire Shopify customer email list as a Custom Audience. Create a 1% Lookalike from this. Meta looks at who your buyers are and finds similar people. This is the most commonly used seed audience and a solid starting point for any Shopify store.
Seed 2: High-Value Customer List (Best for ROAS)
Export your top 20% customers by lifetime value from Shopify. Upload as a separate Custom Audience. Create a 1% Lookalike from this. Meta finds people who look like your best customers, not just any buyer. This typically yields better ROAS than the all-customers Lookalike because Meta is modelling from high-value buyers specifically.
Seed 3: 180-Day Recent Purchasers (Best for Currency)
Create a Custom Audience from your Pixel’s Purchase events in the last 180 days. Create a 1% Lookalike from this. These are recent buyers, whose behaviour is more reflective of current market conditions than all-time buyers going back years.
Seed 4: Checkout Abandoners (For Prospecting Similar High-Intent Users)
Create a Custom Audience from users who fired InitiateCheckout but not Purchase. Create a 2–3% Lookalike. Meta finds users who look like people who were close to buying. Less precise than buyer-based Lookalikes but can be useful for reaching high-intent prospects.
How to Create a Lookalike Audience in Meta Ads Manager
- Go to Audiences → Create Audience → Lookalike Audience
- Select the source: choose your Customer List Custom Audience or your Pixel-based Purchase audience
- Select the location: your target country (USA for US-focused Shopify stores)
- Select the audience size: start with 1%
- Click Create Audience
The Lookalike audience takes 1–6 hours to populate. It requires the source audience to have at least 100 matched people in the target country. If your source has fewer than 1,000 people, the Lookalike may be less accurate.
Testing Lookalike Audience Performance
A/B test Lookalike vs Interest targeting
Create two identical ad sets: one targeting a 1% Lookalike from your customer list, one targeting interest/demographic-based audiences. Run for 7–14 days with equal budget. Compare cost per purchase and ROAS. For most established Shopify stores, the Lookalike will win.
Test different Lookalike sizes
Create ad sets with 1%, 2%, and 5% Lookalikes. Monitor ROAS. Typically, 1% has the best ROAS but the smallest reach (may have delivery issues for small budgets). 2–3% often balances reach and precision better for scaling.
Test different seed audiences
Compare a Lookalike from all customers vs Lookalike from high-value customers. The high-value seed often performs better at higher budgets. At lower budgets, the all-customers seed may have sufficient size to be more stable.
Lookalike + Advantage+ Audiences
Meta’s Advantage+ audience feature (formerly Broad Targeting) uses Meta’s AI to find the best audiences automatically. You can combine this with Lookalike Audiences by setting the Lookalike as a “suggestion” rather than a strict targeting requirement, allowing Meta to expand beyond the Lookalike if it finds better performing users outside the defined segment.
Keep Your Seed Audiences Fresh
Customer list-based Lookalikes should be refreshed monthly by re-uploading your current Shopify customer export. As your customer base grows, the Lookalike model improves. Pixel-based Lookalikes (from Purchase events) update automatically as new purchases are tracked.
Book your free Shopify tracking audit here and we will help you build Lookalike Audiences from the right seed data for your store’s specific customer base.