What lives at each layer?
| Layer | What you set here | The question it answers |
|---|---|---|
| Campaign | The objective (sales, leads, engagement, traffic, awareness, app promotion), special ad categories, and, if you choose, the budget for the whole campaign | What am I asking Meta to get me? |
| Ad set | The conversion event (purchase, lead, add to cart), the audience, the locations, the placements (Facebook, Instagram, Reels, Messenger, Audience Network), the budget if it is not at campaign level, the schedule | Who sees it, where, and for how much? |
| Ad | The creative: image or video, primary text, headline, description, the button, the landing page URL | What do they see? |
Meta's own description of the structure is in the Meta Business Help Centre, "About the structure of Meta ad campaigns". The practical rule: the objective is the hardest thing to get wrong and the hardest to fix, because changing it means a new campaign.
Why does the objective matter so much?
Because Meta's system builds the whole campaign around it. Ask for traffic and Meta finds people who click, who are not the people who buy; the click is cheap and the sale rarely follows. Ask for sales with a Purchase event and Meta finds people who buy, at a higher cost per click and a far lower cost per sale. Owners who start with a traffic campaign because the clicks are cheap, and later wonder why nothing sells, have met this. The objective is a promise about what you will measure, and Meta holds you to it.
What does a sensible structure look like for one business? (example figures)
A Canberra florist with an online shop and a $1,200 a month budget wants orders, and wants past customers reminded before Mother's Day without paying to find them again.
| Setting | Why | |
|---|---|---|
| Campaign | Objective: sales. Advantage campaign budget: $40 a day | One job, one budget Meta can move between the ad sets |
| Ad set 1: new customers | Purchase event. Lookalike of past buyers, 30 km of Canberra. All placements | The growth half |
| Ad set 2: past customers | Purchase event. Customer list, with the last 30 days of buyers excluded. Feeds and Reels only | The cheap half, kept separate so its results do not hide the first set's |
| Ads, three per set | A video of a bouquet being made, a still of the Mother's Day range, a customer's words over a photo | Variety, so no single ad fatigues the audience |
A month in, ad set 1 brings 38 orders at about $24 each and ad set 2 brings 29 at about $9 each. Because the budget sits at campaign level, Meta has already shifted more of the $40 to the second set; because the two sets are separate, the owner can see that the $9 orders are past customers and the $24 orders are new ones, and judge each against what a new customer and a returning one are worth.
What is the mistake that doubles costs?
Changing things at the wrong layer, and changing them often. Editing an ad set's audience or budget by more than about 20 percent sends it back into the learning phase, where results cost more until Meta has about 50 of them in a week. Owners who adjust the budget every two days keep the ad set in learning permanently and pay the learning price forever. Set it, leave it for a week, read it, then change one thing.
What does Cora do with the structure?
CoraVision reads your Meta campaigns and ad sets every night once Meta is connected, each with its spend, impressions, clicks and results and their value, so the two ad sets in the florist's campaign appear as two lines with their own cost per result, and the dashboard's Meta card shows the last 7 days of cost per acquisition and sales. Mira, the Meta Ads specialist, teaches the structure on your own screen when a strategy in your plan needs a campaign built, and reads the layers with you afterwards. CoraVision never creates, edits or pauses a campaign, ad set or ad itself.
Questions
Should the budget sit on the campaign or the ad set?
On the campaign, as Advantage campaign budget, when the ad sets are variations on one job and you want Meta to move the money to whichever works. On the ad sets when they serve different purposes, such as one for new customers and one for past customers, and you want each to have its own floor.
How many ad sets should a small business run?
As few as the strategies need. One ad set per audience you want to treat differently, and rarely more than three in a campaign. More ad sets split the budget and the learning, and each needs about 50 results a week to settle.
What is the learning phase?
The period after an ad set starts or is changed significantly, while Meta works out who responds. Results cost more during it. Meta says an ad set leaves learning after about 50 optimisation events in seven days, which is why a tiny budget can stay in learning forever.