For an established store, I start by looking for campaigns and ad sets that could share a budget and objective. One consolidated campaign can hold the active creative rotation. Separate campaigns or ad sets need a reason, such as a market with its own budget, a different schedule or an experiment that needs controlled allocation.

The structure should make those decisions easy to carry out and review. Consolidation is useful where settings and goals are compatible; it becomes restrictive when the business needs controls that the combined setup cannot provide.

The default shape, and why it works

A testing CBO sets the budget at campaign level and allocates it across ad sets. Delivery can also concentrate on a few ads within an ad set. Read that concentration alongside purchases, cost and the amount of evidence each ad received. Little or no spend leaves a creative question unresolved, even if replacing that candidate is the practical next move.

A separate ad set or campaign can give a promising ad more deliberate budget. Before moving it, decide what the extra allocation is meant to establish and how much loss you can tolerate. Performance observed at one spend level may not hold at another.

Keep the active rotation small enough to review properly. I cover the budget and concept questions in how many ads to test in a CBO.

Who owns which setting

The campaign owns the objective. The ad set owns the audience, placements, and schedule. The ad owns the creative itself, the format, media, text, links, and page identity. Budget sits at campaign level or ad set level depending on how the campaign was set up, and with a campaign budget Meta distributes spend across the ad sets in real time, inside whatever minimum and maximum limits you have set.

Name the setting that needs to differ before adding a campaign or ad set. A different objective belongs at campaign level. Separate schedules may require separate ad sets. A new creative can often run as another ad in the existing setup.

When do you actually need another campaign or ad set?

Split only when two things truly need different settings at the same time and one entity cannot hold both.

The "at the same time" part is what people miss. An ad set holds one schedule. You can edit that schedule whenever you like, but editing a setting is different from holding two values of it at once. If the UK needs ads running on different hours than the US, with its own budget behind them, one ad set cannot express that, so the UK earns its own. That is a real split. If the difference can live inside one entity's settings, you change the settings and keep the structure.

Each additional campaign or ad set needs a budget, a review and someone responsible for resolving delivery problems. Keep a split when that work buys useful control or information.

Compare the work required by two structures

These are illustrative structures, not a description of every account in a particular year.

What simplification can and cannot solve

Combining similar ad sets can reduce fragmentation. It will not fix an inaccurate Purchase event, a weak product page or a set of ads that all make the same claim. Review those inputs before treating a cleaner account diagram as a performance improvement.

Do I have to rebuild my messy account?

Review the existing campaigns before rebuilding. A campaign that still meets its business target may have no immediate reason to move.

Consolidate in stages where it makes sense. Choose where new creative belongs, stop creating unnecessary copies and review legacy ad sets against their actual purpose and results. Keep a record of each move so you can distinguish its effects from changes in offers, stock or creative.

If uneven delivery prompted the restructure, first follow the CBO delivery checks. Clean statuses do not turn zero spend into a completed creative test.