Meta campaign structure in 2026: what Andromeda changes

In 2026, build one campaign per goal, with as few ad sets as your budget allows: an ad set usually only exits the learning phase after about 50 results per week ^[1]. Put the variation in your ads, not in your audiences. Meta largely decides who sees your ad, and your ad is the strongest signal it has.

Whether you work in Ads Manager yourself or with a Facebook Ads agency, your structure has to follow how Meta selects ads. Below is only what Meta itself publishes, with a rule of thumb for your budget.

How many ad sets can your budget carry?

Divide your weekly budget by your expected cost per result, and the outcome by 50. That is the number of ad sets that can exit the learning phase. During the learning phase, results are less stable and the cost per result is usually higher ^[1].

Even €10,000 a month, at €30 per purchase, carries only one ad set that clears the threshold comfortably. Meta itself recommends combining similar ad sets ^[2]. Ad sets with overlapping audiences also end up in the same auctions, and there Meta only lets your ad with the highest value take part ^[3].

If you don't reach 50, you'll see "Learning limited". According to Meta, that is not a penalty but a sign that your budget isn't working efficiently with these settings ^[4]. You can combine ad sets, broaden the audience, raise the budget or optimise for an event that happens more often ^[4].

Sales, leads and reach do belong in separate campaigns, because each campaign optimises for one type of result. If you run more than one ad set, use a campaign budget: Meta spreads it across the ad sets itself, not evenly but towards the best opportunities ^[5]. What a result costs in your sector is covered in what advertising on Facebook and Instagram costs.

Put the variation in your ads

Three genuinely different concepts are worth more than ten variants of the same image. Think of the problem you solve, a customer doing the talking, and your product in use. How to turn one product photo into several video concepts is covered in from product photo to video ad with AI.

Don't run too many ads at once, though. Each ad then gets fewer impressions, and fewer ads exit the learning phase ^[6]. Meta recommends fewer ads per ad set, with more different images or videos per ad: up to 10 ^[6].

With flexible ad format, Meta chooses per placement and per person which image or video to show ^[7]. Text variants go into one ad with multiple text options ^[6]. When you need new concepts is explained in creative fatigue on Meta.

Test without breaking the learning phase every time

Every significant edit can send an ad set back into the learning phase. Meta counts any change to targeting or creative, a different optimisation event or bid strategy, a pause of 7 days or longer and a new ad as significant edits ^[8]. For budget, the size of the change matters: from $100 to $101 probably not, from $100 to $1,000 possibly ^[8].

• Add new ads in batches. Three concepts at once every two weeks rather than one every day.
• Let winners run. Meta decides for itself how many impressions each ad gets.
• Test big questions with Meta's A/B test. Switching ad sets on and off by hand gives overlapping audiences and unreliable results ^[9].
• Judge over weeks, not days. During the learning phase, results say little about what follows ^[1].

If you use a campaign budget, a new ad set doesn't send the other ad sets in that campaign back into the learning phase ^[8]. The rules, the calculation table and a ten-point check of your account are combined in the cheat sheet.

Prefer a second pair of eyes? The free Meta Ads audit goes through structure, measurement, audiences, creative rotation and budget allocation.

What Advantage+ still leaves to you

With Advantage+ audience, location, minimum age, language and excluded custom audiences remain hard limits. Age, gender, interests and included audiences are suggestions Meta may deviate from ^[10]. If you choose Sales, Leads or App promotion, you start in the Advantage+ setup ^[11].

If you restrict your budget, audience or placements too much, Ads Manager shows "Advantage+ off" ^[12]. Raising the minimum age up to 25 or excluding a custom audience is still possible ^[12]. Excluding by interests has not been possible since 31 March 2025 ^[13]; how to solve that with your own data is covered in audiences on Meta after iOS and cookies.

A deliberate choice is still needed in three places:

• Excluding existing customers with a custom audience: a hard limit, even with Advantage+ ^[10].
• Retargeting: Meta recommends A/B tests with Advantage+ audience for almost all campaigns, except retargeting ^[14].
• Special ad categories: if you advertise financial products, employment or housing, you have no access to Advantage+ audience ^[10].

What makes Belgium different

Don't create separate ad sets per language. Meta recommends combining languages in one ad set ^[6]. With dynamic language optimisation you create one ad in up to 48 languages, and Meta shows each person the right version, although that only works with a single image or a single video ^[15].

Belgian audiences are also small. At the end of 2025, Meta's advertising tools reported a reach of 6.20 million people on Facebook in Belgium ^[16]. A radius around your business quickly leaves only a few tens of thousands of them, and Meta recommends bundling small areas ^[6].

What Andromeda is, and what it isn't

Andromeda is the first selection step in Meta's ad system. It narrows tens of millions of ad candidates down to a few thousand relevant ones ^[17]. Meta Engineering introduced it on 2 December 2024, as the engine behind Advantage+ ^[17].

It is not a button and not a new campaign type. Articles that date Andromeda to 2025 or attach ROAS gains to it have no primary source for that: the engineering post only gives technical measures of the system ^[17].