Facebook ad copy formulas: PAS, AIDA and BAB with examples

Copywriting formulas are not magic. They are checklists for the order in which a reader needs information. On Facebook and Instagram, where primary text sits next to a scroll-stopping visual and is often cut off after a line or two, that order matters more than usual.

This guide covers the three formulas most useful for ad copy, PAS, AIDA and BAB, with full example primary texts for two fictional products: Lumen, a fragrance-free moisturizer, and Stride, a standing desk mat. Writing both products in every formula shows how the same facts read differently depending on the structure. It then covers 4U and FAB briefly, compares when to use each, and finishes with length guidance.

PAS: problem, agitate, solution

PAS names a problem, makes it vivid, then presents the product as the way out. It is the most dependable formula for prospecting to problem-aware audiences because it starts where their attention already is.

• Problem: state it in the reader's words.
• Agitate: show the cost of leaving it unsolved, with specifics rather than drama.
• Solution: introduce the product and why it works, then the call to action.

Lumen, PAS

Moisturizer shouldn't sting.

Yet for reactive skin, a lot of them do. Fragrance, essential oils and long ingredient lists can mean tightness by mid-morning and a shelf of half-used jars nobody wants to finish.

Lumen Daily Cream has nine ingredients and no fragrance. It sinks in within a minute and sits well under sunscreen.

Try it for 30 days. If it doesn't suit you, we'll refund you.

Stride, PAS

Standing desks were meant to fix the 3pm slump.

For a lot of people they just move the ache from the lower back to the feet. Hard floors give nothing back, so after an hour you shift, lean, and end up sitting again.

The Stride mat has a cushioned surface with a raised ridge and sloped edges, so your feet have somewhere to move and standing stays comfortable for longer.

Free delivery across the UK and EU. Shop the mat.

Notice that the Lumen copy never says "you have sensitive skin". Meta's advertising standards restrict copy that asserts or implies personal attributes, including health conditions, so describe the situation rather than the reader.

AIDA: attention, interest, desire, action

AIDA is the oldest of the three and the most flexible. It suits audiences who are not yet feeling the problem and need a reason to care.

• Attention: an unexpected line or fact.
• Interest: what the product is and what makes it different.
• Desire: help the reader picture owning it.
• Action: a clear next step, ideally with a reason to act now.

Lumen, AIDA

Nine ingredients. That's the whole list.

We made Lumen Daily Cream for skin that reacts to almost everything, so we left out fragrance, essential oils and drying alcohols, and kept only what does the work.

Light enough for mornings under SPF, rich enough for winter evenings. One tube, one step, nothing else to think about.

Order by Thursday for delivery this week.

Stride, AIDA

This desk mat has a hill in the middle.

It's there on purpose. The ridge and sloped edges give your feet different positions to move between while you stand, instead of locking you into one.

Slide it under your desk, stand through a meeting, and you'll notice you stop counting the minutes until you can sit down.

Two sizes. Free returns for 60 days.

BAB: before, after, bridge

BAB paints the current situation, then the improved one, then shows the product as the bridge between them. It suits transformation and convenience products and pairs naturally with before and after visuals.

• Before: the reader's world now.
• After: the same world with the problem solved.
• Bridge: how the product gets them there.

Lumen, BAB

Before: a bathroom shelf of moisturizers, each one used twice and abandoned.

After: one cream you reach for morning and evening without thinking about it.

The difference is a short ingredient list. Lumen Daily Cream has nine ingredients, no fragrance and nothing you need a chemistry degree to pronounce. Shop the full size or the travel duo.

Stride, BAB

Before: a standing desk you haven't stood at since the first week.

After: standing through calls and focused work, then sitting because you choose to, not because your feet gave up.

The bridge is what's under you. The Stride mat cushions hard floors and gives your feet room to shift. Free delivery this week.

Two more formulas worth knowing

4U

4U is a test for headlines and first lines rather than a full structure. A strong line is:

• Useful: it promises a benefit.
• Urgent: there is a reason to act now.
• Unique: not every competitor could say it.
• Ultra-specific: it uses concrete details.

Few lines hit all four, so use it to score options. "Great desk mat on sale" scores low. "Stand through your afternoon meetings: the Stride mat, free delivery until Sunday" scores much higher.

FAB

FAB stands for features, advantages, benefits. It turns a spec into a reason to buy.

• Feature: what it is. "High-density foam core."
• Advantage: what that does. "It doesn't flatten over time."
• Benefit: why the reader cares. "It feels the same in month six as on day one."

FAB is most useful in product-aware retargeting, carousel cards and the body of longer copy, where readers want detail.

When to use which

Formula	Structure	Best for	Awareness level	Watch out for
PAS	Problem, agitate, solution	Prospecting with a clear pain point	Problem aware	Over-agitating into fear, or implying personal attributes
AIDA	Attention, interest, desire, action	New or novel products, broad audiences	Unaware to solution aware	Losing the reader between attention and action
BAB	Before, after, bridge	Transformation and convenience products	Problem aware	Promising an "after" you cannot substantiate
4U	Useful, urgent, unique, ultra-specific	Headlines and first lines	Any	Forced urgency that is not real
FAB	Feature, advantage, benefit	Retargeting, carousels, detailed products	Product aware	Listing features without the benefit

How long should primary text be

Length depends on the product and how much the audience already knows, but a few practical rules hold.

Element	Practical guidance	Why
First line	Make it work on its own within roughly the first 125 characters	Many placements cut primary text off with "See more" around there, though the exact point varies by placement and device
Short copy	One to three lines	Impulse buys, offers and retargeting, where the visual does the work
Long copy	Several short paragraphs	Considered or higher-priced products that need explanation and proof
Headline	A few words	Space is tight and often truncated on mobile
Line breaks	Short paragraphs, one idea each	Long blocks are hard to read on a phone

Meta's ad specs have long recommended around 125 characters of primary text, but treat that as the visible preview rather than a limit. Test short and long versions of the same formula; it is a cheap test and the answer differs by account. Preview every ad on mobile before publishing, and use a character counter to check where your lines will break.

Putting it into practice

The fastest way to get good at these formulas is to read a lot of real ads and label them. In PixelSpyer's ad library you can filter by niche, language and call to action, then read the primary text of ads that have run for weeks and note which structure each one uses. When you are ready to draft, the free ad copy generator produces variations to work from, and our ad hook formulas give you stronger first lines to open with.