When running both Advantage+ Shopping Campaigns (ASC) and manual interest-based campaigns, cannibalization becomes a real issue — especially as Meta’s AI expands beyond its initial targeting. The ASC might start stealing impressions or conversions that your manual campaigns used to win.
Here’s how to stop that without killing performance:
1. Exclude Custom Audiences in Advantage+ Campaigns
Why: Advantage+ campaigns can reach warm audiences by default — including your website visitors, add-to-carts, or purchasers — even if you’re already targeting them manually.
How:
Go to your Advantage+ Shopping campaign
Scroll to “Audience Controls”
Under “Existing Customers,” click “Add exclusions”
Exclude:
Your website custom audience
Add-to-cart and purchaser audiences
Any interest-based segment you’re using in manual campaigns
This forces Advantage+ to focus only on cold acquisition, not steal retargeting traffic or interest segments.
2. Cap Existing Customer Spend (ASC setting)
Why: If you're targeting warm audiences in another campaign, you don’t want ASC to overspend on them.
How:
Within ASC setup, scroll to:
“Existing Customer Budget Cap”
Set it to something low (e.g., 5–10% of your total ASC budget)
This limits the budget ASC can spend on people Meta identifies as “likely existing customers.”
3. Stagger Budgets Intelligently
Why: Meta favors higher-budget campaigns in the auction. If ASC has a much larger budget than your manual campaign, it’ll win more impressions — even from your intended interest targets.
How:
Keep budgets of both campaigns relatively balanced
If your manual campaign is for testing audiences, keep its creative unique to avoid creative overlap (see next point)
4. Use Distinct Creatives per Campaign
Why: When the same creative exists in multiple campaigns, Meta doesn’t respect audience boundaries — it sends most traffic to whichever campaign it believes will perform better (usually ASC).
How:
Give your manual campaign exclusive creatives — change the hook, text, or visual format
Label ad names clearly: Creative-A_SC vs Creative-A_Manual
Pro tip: You can test the same concept in both campaigns, just make sure there’s variation in the execution.
5. Compare Performance with UTMs
Why: Cannibalization isn’t always visible in Meta’s UI. A drop in performance in your manual campaign might be caused by ASC overlap.
How:
6. Use Campaign Priority (Shopify & Commerce Manager)
If you're using Shopify’s Facebook integration, there’s a setting for “Campaign Priority.” Assign manual campaigns a higher priority for warm traffic or niche targeting.
