Most marketing consultancy engagements go wrong before anyone logs into an ad account. The brief says "fix our paid social" or "we need an email strategy", the consultant agrees, delivers exactly that, and three months later revenue looks the same. Everyone did their job. The business didn't move.
I've worked as a fractional growth lead across three or four brands at a time, on engagements that ran for years, and I now consult independently. I've also spent years on the other side of the table hiring agencies as a Head of Marketing. The pattern is consistent. The engagements that change revenue are scoped around a commercial problem. The ones that don't are scoped around a channel.
Here's how I'd scope a marketing consultancy engagement if you want it to show up in the numbers.
Start with the revenue problem, not the marketing brief
Before you talk about deliverables, write the problem down as a single commercial sentence. Something like: "We do £80k a month online at a loss and need to be profitable at that level within six months." Or: "New customer acquisition has stalled and we can't afford to pay more per customer."
That sentence should include where revenue is now, where it needs to be, by when, and what margin constraint you're working under. If you can't fill those in, that's fine, but it tells you the first piece of work is finding out, not running campaigns.
Compare that with "we need a TikTok strategy". It might be the right answer. It's a terrible starting brief, because it has already decided the solution and gives nobody a way to judge success other than whether the TikToks went out.
A practical test for this week: take your current brief and ask, "If this was delivered perfectly, how would our P&L look different?" If nobody can answer, rewrite the brief.
Pay for a diagnosis before you commit to a scope
The single best change most businesses can make is to split the engagement in two. A short, fixed-fee diagnostic first. Then the main body of work, scoped on what the diagnostic found.
As a rule of thumb, two to four weeks is enough for a diagnostic on a small or mid-sized DTC brand. In that time a good consultant should look at unit economics (what you actually make per order after product, shipping, returns and acquisition cost), the funnel from first visit to repeat purchase, channel performance, and the operational bits that customers feel but marketing teams rarely own.
The output should be a short written document that ranks the constraints on revenue by likely impact. Not a 60-slide deck. A ranked list with reasoning behind it.
This protects both sides. You don't sign up for six months of work aimed at the wrong problem, and the consultant doesn't get boxed into promising results from a channel that was never the bottleneck. If the diagnostic doesn't surprise anyone in the business, I'd question how deep it went.
Scope the customer journey, not the channel
This is where most scopes are too narrow. Revenue is made or lost across the whole journey, and a lot of it sits outside what's normally called marketing.
At Fields Luxury, I owned the full P&L for two watch brands, Swan & Edgar and Anthony James. Both were loss-making when I picked them up. If I'd scoped that as "improve the ads", I'd have been pushing low five figures a month in ad spend into a business that leaked margin after the sale. The work that turned both brands profitable went well beyond marketing. We moved manufacturers for some models, changed shipping and packaging, reworked customer touchpoints, brought returns down, and raised average order value with accessories and cross-sell.
None of that would have appeared in a typical marketing scope. All of it moved profit.
So when you scope an engagement, give the consultant permission to look at, and recommend changes to, anything that affects what a customer pays and what you keep. That usually means product range and pricing, fulfilment, packaging, returns policy, customer service scripts and post-purchase emails. They don't have to own all of it. They do need to be allowed to say "this is the problem" when it isn't a marketing problem.
If a consultant only ever recommends things in their own specialism, be suspicious.
Agree who owns what, in writing
A consultant without decision rights is an expensive opinion. Before the engagement starts, be explicit about three things.
First, access. Read access to the ad accounts, analytics, ecommerce platform and email tool on day one. Ideally sight of the P&L or at least contribution margin by channel. You can't scope for revenue and then hide the revenue.
Second, decisions. Who can change budgets, pause campaigns, brief creative, and change on-site copy or offers? Who needs sign-off for what, and how fast will sign-off happen? A two-week wait for approval on a landing page change quietly kills more engagements than bad strategy does.
Third, agencies and suppliers. If you have agencies in place, agree whether the consultant can brief them, review their work and recommend replacing them. At Fields Luxury we went through two content agencies and three ad agencies before landing on the right ones. That churn was painful but necessary, and it only worked because someone had clear authority to make the call and judge the results against commercial numbers rather than activity reports.
Put all of this in the statement of work. It feels bureaucratic. It saves months.
Measure money, not activity
Pick three to five metrics that tie directly to revenue or profit, and baseline them before work begins. For most DTC and consumer brands, I'd choose from this list:
- Contribution margin per order, after product cost, shipping, returns and acquisition
- Revenue from new customers versus returning customers
- Blended customer acquisition cost and how long it takes to pay back
- Repeat purchase rate within a set window
- Return rate, if it's a category where returns hurt
ROAS is useful, and I've spent years optimising it, but on its own it can hide a lot. A campaign can hit a strong ROAS on discounted products that barely make money once returns come back. Measure it alongside margin, not instead of it.
Leading indicators like click-through rate, email open rates or follower growth are fine for day-to-day management. They shouldn't be what the engagement is judged on. If a consultant's proposed success metrics are mostly activity, push back and ask how each one connects to the P&L.
One more thing. Agree how attribution will be handled before results come in. Arguments about which channel gets credit are far less heated when the method was settled in month one.
Set the length, the rhythm and the exit
Revenue rarely moves in four weeks. It also shouldn't take a year to see any signal. A sensible default is to scope in 90-day blocks after the diagnostic, with a clear review at the end of each block where either side can change direction or stop.
Within each block, keep the rhythm light. A short weekly written update covering what changed, what the numbers did and what's next. A monthly review against the agreed metrics. Most of my own reporting runs through AI tools I've built for the purpose, which keeps the weekly update quick to produce and means the time goes into the work rather than the slides.
Then plan the exit from the start. What should the business be able to do without the consultant when the engagement ends? Documented processes, email flows that run on their own, a paid media structure the in-house team understands, a hiring plan if the work has shown you need a permanent role. If the scope doesn't say what gets handed over, you're renting expertise rather than building it.
A one-page scope that covers the commercial problem, the diagnostic, the areas the consultant can touch, decision rights, three to five metrics with baselines, the 90-day plan and the handover is enough. If it needs ten pages, it's probably padded.
FAQ
How long should a marketing consultancy engagement last?
Start with a two to four week diagnostic, then work in 90-day blocks with a proper review at the end of each one. Some engagements are done in a single block. Others run for years when the consultant is effectively acting as a fractional head of growth. The length should follow the problem, not the other way round.
Should a consultant be paid on results?
A performance element can align incentives, but be careful. Revenue is affected by stock, pricing, seasonality and decisions the consultant doesn't control, so pure results-based pay tends to push people towards short-term wins like heavy discounting. A fixed fee with a modest bonus tied to agreed margin metrics is usually a fairer balance.
What's the difference between hiring a marketing consultant and an agency?
An agency is usually paid to execute a channel well. A consultant should be looking across the whole business to find where revenue is being won and lost, then deciding what gets executed, by whom. Many brands need both. The consultant's job is often to brief, manage and judge the agencies against commercial results.
If you're scoping a piece of growth work and want a second opinion, or you're looking for someone to own marketing and growth properly, I'm open to Head of Marketing and Head of Growth roles, with DTC and consumer brands first, and I take on consulting work alongside that. Get in touch through the contact link on tomosborne.me and tell me what the revenue problem is. That's always the best place to start.