CBO vs ABO in Meta Ads 2026: Which One Should a Store Use?

By Thisura, founder of Run1Ads · 2026-11-02

Quick answer

Use ABO (a budget on each ad set) when you are testing creatives or audiences, and use CBO (one budget on the campaign) when you already have winners and want Meta to scale them. Meta now calls CBO "Advantage+ campaign budget" and, according to Segwise, defaults new campaigns to it, so the real question in 2026 is when to switch it off. For most stores, a small number of ad sets with one clear job each beats a pile of ad sets fighting for the same budget.

What is the difference between CBO and ABO?

With ABO (ad set budget optimization) you give every ad set its own daily or lifetime budget. Meta spends that money inside that ad set only, even if another ad set is doing better.

With CBO (campaign budget optimization, now shown as Advantage+ campaign budget) you set one budget for the whole campaign. Meta moves the money between ad sets in real time toward whatever looks cheapest to convert. Segwise gives an example: a $100 daily campaign budget could end up as $70, $20 and $10 across three ad sets.

Why would I turn CBO off if it moves money to the best ad set?

Because "best" is decided early, on little data. Segwise notes that under CBO Meta might spend most of the budget on one ad set and almost nothing on the rest. That is fine when you are scaling something proven. It is a problem when you are testing, because the ad sets that got little spend never had a fair chance, so you cannot tell if they were weak or just ignored.

ABO fixes that. Each ad set gets the same money, so the comparison is clean. This is why the common rule is to test with ABO, then scale with CBO.

How many ad sets should an online store run?

Meta has not published a magic number, and the sources I read do not give one either. A practical way to decide:

1. Give every ad set one job: one audience or one creative idea to test, not several.
2. Keep the targeting the same across ad sets when you are testing creatives.
3. Make sure each ad set can get enough results. Segwise, citing Meta guidance, says an ad set generally needs about 50 optimization events within 7 days to leave the learning phase.
4. If your budget cannot produce about 50 purchases a week per ad set, run fewer ad sets so each one gets enough data.

More ad sets means the same budget is split thinner. If you spend $50 a day, ten ad sets will each get about $5, which is rarely enough to learn anything. For how creative volume fits in, see our guide on how many creatives Andromeda needs.

Do interests still matter, or should I go broad?

Segwise lists broad audiences as a case where CBO works well, and lists "broad vs lookalikes" as a test you can run in ABO. That is the safe way to answer it for your own store: do not guess, test it. Put broad and one interest audience in two ad sets with the same creative and the same budget, run them for a few days, and compare ROAS from real orders. Meta has not confirmed in anything I read whether turning on detailed targeting expansion makes an interest ad set behave like broad, so check that setting in Ads Manager and treat the test result as your answer.

How do I set up a test then scale campaign?

The setup Segwise describes works for most stores:

1. Create a test campaign and switch off Advantage+ campaign budget.
2. Give each ad set a budget of about 2x your target cost per purchase, for example $40 a day if your target is $20.
3. Let it run 3 to 5 days, then pause the clear losers.
4. Put the winning creatives in a new CBO campaign instead of switching the old one. Segwise warns that changing the budget structure of a running campaign can reset learning.
5. In the CBO campaign you can set a minimum spend on each ad set, about 10 to 20% of the campaign budget, for the first week. Then remove it so Meta can allocate freely.
6. When scaling, raise the budget by about 10 to 20% every few days.

Frequent edits also hurt. Read why in our post on how campaign edits reset delivery.

How do I check whether my structure is hurting my sales?

Ads Manager results alone can mislead you, because it shows what Meta counted, not what your store sold. Once a week, compare three numbers for the same dates:

1. Purchases and revenue in Ads Manager, per campaign.
2. Orders and revenue in Shopify or your store, from the same source.
3. ROAS from real orders: store revenue divided by ad spend.

If a CBO campaign shows one ad set eating most of the budget, check that ad set against real orders, not only Meta's number. If the store shows fewer orders than Meta claims, fix tracking before you change the structure. Our Pixel fix guide walks through it.

How do I check this automatically?

Run1Ads compares how your campaigns are set up with your store goal, and tracks ROAS as budgets change, so you can see whether a move from ABO to CBO helped or hurt. It reads your ad account with read only access, checks every hour, and tells you the one fix that matters today. You can see it in the live demo.

Key facts

• Segwise (article published 27 March 2026, updated July 2026) says Meta now runs CBO as Advantage+ campaign budget and defaults new campaigns to it.
• Segwise says each ad set generally needs about 50 optimization events within 7 days to leave the learning phase, citing Meta.
• Segwise suggests an ad set test budget of about 2x your target cost per purchase, for example $40 a day for a $20 target.
• Segwise suggests a minimum spend of about 10 to 20% of the campaign budget per ad set during the first week of a CBO campaign.
• Segwise suggests raising CBO budgets by about 10 to 20% every few days.
• Segwise says switching a running campaign from ABO to CBO can reset learning, and suggests a new CBO campaign instead.

FAQ

Is ABO or CBO better in 2026?

Neither wins every time. ABO is better for testing because every ad set gets equal money. CBO is better for scaling because Meta can push money toward proven ads. Most store owners use both, in separate campaigns.

Can I still use ABO now that CBO is the default?

Yes. Segwise says you can still switch off Advantage+ campaign budget and set budgets on each ad set. That is what makes ABO useful for tests.

Does CBO spend more than ABO?

No. Segwise says CBO uses the same campaign budget you set and only spreads it differently, so the total does not grow. It can feel like more because one ad set takes a large share.

Is there a tool that checks my campaign structure for me?

Yes. Run1Ads is a live Meta ads consultant that compares your store goal with how your campaigns are set up and tracks ROAS as budgets change. It is read only, so it advises and never changes your account unless you ask.

Related reading

• How Many Creatives Does Meta's Andromeda Algorithm Need?
• Your Campaign Edits Are Resetting Meta's Delivery, Not the Algorithm
• Meta Pixel Not Tracking Purchases? A Step by Step Fix

Run1Ads is a live Meta ads consultant for e-commerce brands. It checks your ads, Pixel and store every hour and tells you the one fix that matters today. See the live demo or start free, no card needed.