Knowing how to brief an agency removes most of the waste from the first month. That month is usually half setup and half archaeology — working out what the business actually sells, to whom, at what margin, and what has already been tried. Almost all of it is avoidable.
Decide these three things internally first
1. What a customer is worth. Contribution after cost of goods, delivery, fees and returns. Not revenue. If you do not know, work it out before the first call — our contribution margin calculator takes five minutes and changes every subsequent conversation.
2. What success looks like, as one number. Cost per customer, cost per qualified opportunity, blended efficiency. One, agreed in advance, with a baseline. Not "more leads" and not three metrics that can be swapped when one looks bad.
3. Who approves creative, and how fast. The most common reason a competent agency underperforms is that nothing could be approved. If three people must agree and one travels, say so up front so it can be designed around.
How to brief an agency: what to send
- Access to the ad accounts, analytics and, if you have one, the CRM — read access is enough to start
- The last twelve months of performance data, and what you think it means
- Your unit economics
- What you have already tried that did not work, and why you think it failed
- Your actual customer — not a persona document, a description of who genuinely buys
- Any compliance constraints, especially in finance, health or regulated categories
- Brand assets, and how much latitude there is to depart from them
"What have you already tried that failed?" is the most valuable question in onboarding and the one clients answer least fully, usually out of embarrassment. It is the fastest way to stop an agency repeating it.
Be honest about the constraints
If the budget is fixed and cannot rise, say so — it changes the strategy entirely. If you need results before a funding round, say that too. If a previous agency left badly and you are sceptical, that is useful information rather than rudeness.
Agencies plan differently for "we can scale if this works" than for "this is all the money there is". Both are workable. Discovering the second in month three is not.
What to ask them for in return
A written audit before any changes. A thirty-sixty-ninety plan. The name of the person actually working on the account. The baseline you are both agreeing to judge against. And a clear statement of what they will tell you at week four if it is not working.
Three questions worth asking yourself before any of it
Can we actually serve more customers? If the answer is no, or not for two months, say so. Generating demand you cannot fulfil damages the business and wastes the budget.
What happens if this works? A campaign that triples enquiries needs someone to call them. Capacity is part of the brief.
What would make us stop? Agree the number at which you pull the budget, in advance, while you are calm. Nobody makes that judgement well three weeks into a disappointing month.
What a good first fortnight looks like
Access, audit, tracking verified end to end, and emergency fixes only. Not a full rebuild in the first three days — that destroys learning your previous spend paid for and makes month one unreadable for both of you.
A brief is only half of it. Running the selection itself decides how useful the responses are, and before you sign, nine clauses in the contract are worth reading carefully. Once appointed, the access checklist is what stops week one disappearing into chasing logins, and these fifteen questions are the ones to ask before any of that.
Our version of the sequence is on the process page. If you want the audit before committing to anything, it is free.
Questions people ask
How long should an agency brief be?
Two pages is normally enough. Length is not the point — margin, close rate and what has already been tried are worth more than ten pages of brand background.
Should I tell an agency my budget?
Yes. Withholding it produces a proposal for a business that does not exist, and you then spend a call correcting it. Tell them the budget and the return it has to produce, and judge the answer.
What if my tracking is a mess — should I say so?
Say so immediately. Every agency finds out in week one anyway, and hiding it means the first month’s plan is built on numbers nobody trusts. Honest mess is a normal starting point.
What should I ask the agency to send me?
Their first-thirty-days plan, the named person running the account and how many others they carry, and a redacted report they sent a client last week. All three are easy for a good agency and awkward for the rest.