# CBO vs ABO: campaign budget vs ad set budget

> CBO lets Meta split budget across ad sets. ABO fixes a budget per ad set. Which to use for testing and for scaling, with a worked example.
- **Author**: Marxx
- **Published**: 2026-10-21
- **Category**: Meta
- **URL**: https://marxx.ai/library-compare/cbo-vs-abo

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Use ABO (ad set budget) when you want each test to get a fair share of spend. Use CBO, now called Advantage+ campaign budget in Meta's Help Centre (checked 2026-10-20), when you want Meta to push money to whatever performs best. Many teams test with ABO and scale with CBO.

## The difference

| | CBO (Advantage+ campaign budget) | ABO (ad set budget) |
|---|---|---|
| Budget set at | Campaign | Each ad set |
| Who splits it | Meta, in real time | You |
| Good for | Scaling winners | Fair tests between audiences or concepts |
| Risk | One ad set takes nearly all spend | Money stays on weak ad sets until you move it |

## A worked example

You test three audiences at INR 9,000 a day.

**With CBO:** after two days, Meta sends INR 7,400 a day to audience A, INR 1,200 to B and INR 400 to C. You get the best short-term result, but B and C never got a real test.

**With ABO at INR 3,000 each:** after a week, A costs INR 620 per purchase, B INR 590 and C INR 1,100. B is actually best. CBO would have hidden it.

Next step: move A and B into one CBO campaign to scale, and drop C.

## When to use each

- **Testing new audiences or concepts:** ABO, equal budgets.
- **Scaling proven ad sets:** CBO.
- **Few ad sets with similar audiences:** CBO works well.
- **Very different audience sizes** (a tiny retargeting set and a broad set): ABO, or CBO with minimum spend limits.

## FAQ

### Is CBO better for the learning phase?

It can help, because Meta moves budget to the ad sets that get results. But each ad set still needs about 50 results in the week after its last big edit to leave the learning phase (Meta's guide, checked 2026-10-20).

### Can I set limits inside CBO?

Yes. Meta lets you set a minimum or maximum spend for each ad set (checked 2026-10-20). That helps when one ad set would otherwise take everything.

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