Duplicating a winning ad set degrades performance 15–25% per copy

Duplicating a winning ad set degrades performance 15–25% per copy

The scale instinct: 'this set works, let me run 3 of it.' Copies compete against the original in the same auction — you bid against yourself.

Duplicate-and-scale outcomes (28 accounts):
— Original set CPA: $24
— Duplicate #1 CPA: $28 (+17%)
— Combined CPM lift: +19% (self-competition)

Meta even flags this as 'auction overlap' but most buyers ignore it.

Fix: scale vertically (raise budget ≤20%/48h on the winner) before scaling horizontally. If you must duplicate, change something material — new creative angle or distinct geo — so copies don't fish the same pond.

Read: a copy that competes with its parent isn't 2× the winner — it's two losers fighting over one auction.