The essentials
- A useful brief: one to two pages, a numerical objective, an audience described by its situations rather than by its age, a clear offer and a real budget.
- The figure most often missing: the value of a conversion (margin per sale, value of a lead). Without it, the agency cannot set a target cost.
- Minimum budget for 2026: €1,000 to €1,500 per month on Meta to obtain usable data, €2,500 on LinkedIn, €1,000 on TikTok.
- Measurement: the brief states who installs the pixel and the conversions API, which event counts, and where the reporting will be read.
A social ads campaign brief serves one purpose: allowing the provider, internal or external, to propose the right set-up first time. Briefs that fail share the same gaps: a vague objective (“build awareness”), a demographic audience (“women aged 25-45”), an undisclosed budget and no indication of measurement. Here are the eight sections of a brief that works, with the level of detail expected for each.
The eight sections of the brief
| Section | Expected contents | The full destination URL |
|---|---|---|
| 1. Objective | A single main objective, with a figure and a date | 120 qualified quote requests between 1 October and 15 December |
| 2. Value of a conversion | Margin per sale or value of a lead, sales conversion rate | A lead is worth €90 (basket €1,800, margin 25%, 20% closing rate) |
| 3. Audience | Situations, purchase triggers, objections, geographic area | Homeowners in detached houses, renovation project within 6 months, Île-de-France |
| 4. Offer | What is on offer and why it is preferable to the alternatives | Quote within 48 hours with a site visit, ten-year guarantee, financing |
| 5. Budget | Media budget, fees, production, period | €9,000 of media over 10 weeks, excluding video production |
| 6. Platforms and formats | Preferred platforms or open to recommendation, brand constraints | Meta as the priority, TikTok test if budget allows, no LinkedIn |
| 7. Creative | Available assets, rights, brand guidelines, who produces what | 12 site photos, 2 video testimonials, vector logo; the agency produces the edits |
| 8. Measurement and reporting | Events to track, tools, frequency and recipients of the reporting | “Quote” form as the conversion, pixel + API, weekly review |
Sections 1 and 2: the objective and its value
The section most often missing is the value of a conversion. Yet it determines everything else: the acceptable cost per lead, the budget required, the choice between prospecting and retargeting. The calculation is simple: average basket multiplied by the margin, multiplied by the sales conversion rate. A lead worth €90 allows a target cost per lead of around €30 to €45; a lead worth €15 allows almost nothing on LinkedIn. The choice of campaign objective itself is set out in detail in which objectives to choose for a social ads campaign.
If you do not yet know these figures, say so and provide what you have: monthly number of sales, average basket, estimated closing rate. An honest approximation is better than an invented objective.
Section 3: describing the audience by its situations
Platforms target less and less on declared criteria and more and more on behavioural signals. A demographic brief therefore barely helps the algorithm; it does, however, help the person who will write the ads. Describe:
- The trigger: what happens in the customer's life at the moment they look for your offer.
- The alternatives they are considering (a competitor, doing nothing, doing it themselves).
- The objections your sales team hears, word for word.
- The distinct segments if there are any, with their share of revenue; the method is set out in audience segmentation in SMA.
Section 5: a real and complete budget
Hiding the budget “to see what the agency proposes” produces unsuitable proposals in both directions. Give the envelope and its breakdown. The thresholds below which a campaign does not produce usable data in 2026:
| Platform | Minimum media budget per month | Why |
|---|---|---|
| Meta (Facebook, Instagram) | €1,000 to €1,500 | Around 50 conversions per week and per ad set are needed to stabilise learning |
| €2,500 to €3,000 | CPC of €5 to €12; below that, fewer than 300 clicks per month | |
| TikTok | 1 000 € | Low CPM but a higher volume of creative required |
Add the fees (15 to 20% of media at an agency, or a flat fee of €500 to €1,500 per month) and the production of the creative. The full orders of magnitude are in what budget to plan for an SMA strategy.
Section 8: measurement, decided before launch
The brief must name the event that will count as a conversion, who installs the pixel and the conversions API, and where the results will be read. Without this section, the first report arrives with figures that do not match between the platform and GA4, and the test month is lost. Specify:
- The main conversion event and the intermediate events (add to basket, contact request).
- The verification tool: GA4 with UTM parameters on every ad, as explained in sources, mediums and UTM.
- The reporting frequency and the three metrics that will be looked at, not fifteen.
- The decision rule: at what cost per conversion the campaign is stopped or scaled up.
The costliest brief mistakes
- Several objectives given equal weight: awareness, traffic and sales at the same time produce a campaign that optimises nothing.
- The “same as the competitor” brief: you know neither their budget nor their results.
- Creative imposed without testing: a visual approved by management is not a visual that converts; plan for three to five variants.
- The absence of constraints: legal notices, regulated sectors (health, finance, alcohol), excluded countries, forbidden tone.
- An unrealistic schedule: allow ten working days between the approved brief and going live, half of that for measurement and creative.
How GreenRed helps
Rather than juggling several tools, GreenRed's Social media SMO / SMA module brings these metrics together in a single dashboard, compares them over time and tells you which actions come first. You can try it free, with no card, from the Pricing.
Frequently asked questions
How long should a social ads campaign brief be?
One to two pages is enough, plus the appendices (brand guidelines, assets, sales exports). A ten-page brief is rarely read in full; a one-paragraph brief forces the provider to guess. The essentials fit into the eight sections: numerical objective, value of a conversion, audience, offer, budget, platforms, creative, measurement.
Should the brief state the platforms or let the provider choose?
State your preferences and your exclusions, then leave room for recommendation. A competent provider will argue from your audience and your budget: LinkedIn for a high-value B2B lead, Meta for B2C and e-commerce, TikTok for an audience under 35 with video creative.
Should the brief contain examples of ads?
Yes, as references, not as instructions. Three competing or inspiring ads, with what you like and dislike about them, calibrate the tone faster than brand guidelines. Meta's ad library and LinkedIn's make them easy to find.
What if you do not know the value of a lead?
Reconstruct it from your sales figures: number of quotes sent, closing rate, average basket, margin. Even approximate, this value sets a ceiling for cost per lead. State in the brief that the figure is an estimate to be refined after the first month of the campaign.