Custom Audiences: retargeting website visitors, customer lists, and engagement

Part 5's Core Audience targets people based on a general interest — real, but genuinely uncertain intent. Custom Audiences target people based on their own actual, demonstrated relationship with the business already: a past visit, a past purchase, an existing customer list. This is consistently among the highest-performing audience types in Meta advertising, for the same reason the Google Ads series flagged remarketing as its own highest-converting audience.

Website Custom Audiences: built from the Meta Pixel

Custom Audience: "All Website Visitors — Last 30 Days"
Custom Audience: "Visited /checkout, Didn't Purchase — Last 14 Days"

These depend entirely on the Meta Pixel (part 8) already being installed and firing on the relevant pages — the Pixel is what actually builds these lists in real time as people browse the site. The second audience above — reached checkout but didn't complete purchase — is Bright Leaf Coffee's highest-intent retargeting segment, directly parallel to the cart-abandoner audience the Google Ads series built for the exact same business.

Customer List Custom Audiences

Upload: existing_subscribers.csv (email addresses, hashed automatically before upload)

A business can upload its own existing customer or email list directly, and Meta matches it against real platform accounts (via secure, one-way hashing — Meta never sees the raw email addresses uploaded). This is the direct route to excluding existing customers from cold acquisition targeting (part 5), or conversely, targeting existing customers specifically with a genuinely different message — a renewal reminder, a loyalty offer, something an acquisition-focused ad shouldn't be showing them at all.

Engagement Custom Audiences

Custom Audience: "Engaged with our Instagram in the last 90 days"
Custom Audience: "Watched 75%+ of our brand video"

Built directly from on-platform behavior — anyone who's interacted with a Page, an Instagram profile, or watched a meaningful portion of a video ad. This reaches people who've shown real interest without ever necessarily visiting the website, a genuinely different, earlier-stage population than website-visitor retargeting.

A real retargeting structure for Bright Leaf Coffee

Ad Set: Retargeting — All Visitors (30 days)     → general reminder ad
Ad Set: Retargeting — Cart Abandoners (7 days)     → urgency-driven offer ad
Ad Set: Retargeting — Existing Subscribers          → excluded from acquisition; targeted separately with a referral offer

Three genuinely distinct audiences, each warranting different messaging — a general visitor gets a broader reminder of the brand, a cart abandoner gets a more direct, urgency-focused nudge to complete the specific action they already started, and an existing subscriber gets an entirely different message (referring a friend) rather than being re-shown an acquisition offer for something they already own.

Why Custom Audiences consistently outperform cold targeting

A Custom Audience is built from real, demonstrated behavior — someone who already visited /checkout has shown far more concrete purchase intent than anyone matching a general "specialty coffee" interest, no matter how well-targeted that interest is. This is the exact same underlying principle the Google Ads series applied to remarketing, and it holds just as strongly here: re-engaging existing, demonstrated intent reliably outperforms creating new intent from a cold audience.

Next: Lookalike Audiences — finding new people who resemble an existing customer base, without ever having interacted with the business directly.