Growth consultancy or marketing agency: which one do you actually need?
The two get compared as if they are the same purchase. They are not. One sells a decision, the other sells capacity, and buying the wrong one is how companies end up with beautiful campaigns pointed in the wrong direction.
Side by side
| Criterion | Growth consultancy | Marketing agency |
|---|---|---|
| What you are buying | A decision, then the execution of it | Execution capacity |
| Who owns the revenue number | The consultancy, explicitly | Usually nobody. Agencies own deliverables |
| Ramp time | Weeks, if they know your market | Three to six months is common |
| Who does the work | Senior operators, embedded in your team | Account manager, plus junior executors |
| When results stall | The strategy gets changed | You get more of the same, faster |
| What you get if you leave | A strategy your team can keep running | Campaigns that stop when the retainer does |
| Best for | Unclear positioning, or channels nobody chose | A clear plan and not enough hands |
When each one is the right call
Growth consultancy
- Your product is strong but the market does not understand why it matters
- Marketing is busy and pipeline is flat, and nobody can explain the gap
- You are entering a new segment and the old story does not carry
- Every agency you brief comes back with something generic
Marketing agency
- You already have positioning and a channel plan you believe in
- You need volume: more content, more campaigns, more ad management
- The gap is capacity, not direction
- You have someone in-house who owns the strategy and can brief well
Three things worth knowing first
-
01
Most agency failures are briefing failures
Agencies are often blamed for work that was doomed by the brief. If the positioning underneath is unclear, no amount of execution rescues it, and the agency has no mandate to fix the thing that is actually broken.
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02
Consultancies that leave are only half the answer
The classic consultancy delivers a strategy and walks away, which puts you straight back into the briefing problem. The model only works if the people who wrote the plan stay to run it.
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03
You can need both, in sequence
Plenty of companies should fix strategy first and then scale execution with an agency afterwards. That is a perfectly good outcome and we will tell you when it is yours.
Where Sarpea fits
Sarpea sits deliberately in the middle: we build the strategy and then stay embedded to execute it, because the handover between those two things is where most of the value leaks out. That does mean we are the wrong choice if you only want hands.
“Honestly, we’d been burned by agencies twice before, so I came in sceptical. Sarpea’s initial audit showed us things about our own funnel we didn’t know. A few months in, I keep forgetting they’re not on our payroll.”
Still deciding?
Is a growth consultancy more expensive than an agency?
Not necessarily. A Sarpea retainer costs less than an outsourced agency of comparable scope, because the model is senior-weighted rather than volume-weighted. There are fewer people involved and they are more experienced.
Can we use both at once?
Yes, and it is common. We often set the strategic direction that an existing agency executes against, which usually makes that agency noticeably more effective because the brief is finally clear.
How do we tell which problem we have?
Ask three people on your team who your product is for and why you win. If you get three different answers, you have a strategy problem and an agency will not solve it.
Not sure which you are? Twenty minutes will tell you.
We will say so if the answer is that you need neither of us.