<b>Campaign budget optimization (CBO) sends ~70% of spend to one ad set by day 3 — sometimes the wrong one</b>

<b>Campaign budget optimization (CBO) sends ~70% of spend to one ad set by day 3 — sometimes the wrong one</b>

CBO = Meta distributes budget across ad sets. ABO = you set budget per ad set.

Spend-distribution logs, 26 campaigns:
— By day 3, CBO concentrated ~70% into the early front-runner
— In 1 of 3 campaigns the early winner lost the lead by day 10 — but never got budget back
— ABO test budgets ($20/set, 4 days) found the durable winner ~40% more often
— Hybrid that worked: ABO to crown a winner, then CBO to scale it

CBO optimizes for the fastest starter, not the best finisher.

Read: let ABO pick winners on small flat budgets, hand only the proven one to CBO.