The fractional CMO vs agency choice comes down to one question: do you need someone to decide what to do, or someone to do it? A fractional CMO is a senior marketing leader who works for you part-time and sets the strategy, while an agency is a team you pay to execute a defined scope, usually in one or two channels.
TL;DR: A fractional CMO gives you senior judgement for a few days a month but rarely does the work. An agency does the work but owns its channel, not your number. A full-time in-house hire owns the number but takes months to arrive and costs the most. If nobody in your company is accountable for one growth number today, that gap is the real problem, and none of the three models closes it by default.
The question usually arrives as an argument. Someone says "we need a CMO", someone else says "just get a better agency", and the debate runs for a quarter while the number has no owner. This page compares the three models honestly, then shows a fourth.
What is the difference between a fractional CMO and an agency?
A fractional CMO sells you time and judgement. They usually work one to three days a week, sit in your leadership meetings, set the marketing plan, decide the budget split and manage whoever does the work. They are billed by the day, the hour or a monthly retainer for a fixed number of days.
An agency sells you output. Campaigns, content, ads, search work, design. They are billed on a monthly retainer for a scope, a project fee, or a percentage of ad spend. A good agency has specialists you could never hire one by one.
The cleanest way to see it: the fractional CMO writes the plan, the agency runs part of it. That is why many companies that hire a fractional CMO still keep an agency. Somebody has to do the work, and a part-time executive working two days a week cannot also write the content, fix the site and run the campaigns.
The incentives differ too. An agency is paid to keep and grow its scope, so when you ask it for strategy, the strategy tends to recommend more of what that agency sells. A fractional CMO is paid for time, so the risk is the opposite: lots of thinking, a sharp deck, and execution that depends on people they do not control.
Fractional CMO vs agency vs full-time CMO: side by side
| Fractional CMO | Marketing agency | Full-time CMO or Head of Growth | |
|---|---|---|---|
| What you buy | Senior judgement, part-time | Execution in a defined scope | One person, full-time |
| Who sets strategy | They do | You do, or they propose their own channel | They do |
| Who does the work | Your team or an agency | They do | Their team, which you still need to build |
| Who owns the growth number | Often nobody, formally | Nobody: they own channel metrics | They do |
| Time to start | Weeks | Weeks | Typically 60 to 120 days to hire, plus notice |
| Cost basis | Day rate or monthly retainer | Monthly retainer, project fee or share of spend | Salary, employer on-costs, often equity |
| Biggest risk | Advice without execution | Activity without accountability | Slow, expensive, one skill set |
| What stays when they leave | Whatever they wrote down | Usually the reports | Whatever they wrote down |
For real day rates and monthly retainers by market, see our breakdown of fractional CMO cost.
Is a marketing agency worth it?
An agency is worth it when three things are true. First, you already know which channel works and you need more hands in it. Second, the channel is specialist enough that hiring in-house would take a year to match, such as paid social, PR or technical search work. Third, someone inside your company can brief the agency, read its reports critically and say no.
An agency is rarely worth it when you are really buying strategy. Ask a paid media agency what you should do next and the honest answer is often outside its scope, so you will not hear it. It is also a poor fit when nobody internal can judge the work. Then the monthly report becomes the only scorecard, and the report is written by the people being scored.
The warning sign is easy to spot: every metric in the agency deck is up, and revenue is flat. Clicks, impressions and cost per click are the agency's numbers. Revenue, margin and retention are yours.
Marketing agency vs in-house: should you build a team?
Building in-house buys you context. An employee learns your customers, your product and your politics in a way no outside team will. The price is time and money.
On money, Glassdoor's typical total pay range for a Head of Growth in London runs from GBP 61.8k to GBP 122.6k a year (25th to 75th percentile, October 2026). In Amsterdam it is EUR 65k to EUR 180.6k, and in India INR 19.25 lakh to INR 60.75 lakh. Those are total pay figures, base plus bonus. In the Netherlands, employer on-costs add roughly 25 to 35% on top (Kolibrie Payroll). We break the full bill down in Head of Growth salary.
On time, senior marketing searches commonly take two to four months, and notice periods in India often add two to three more. That can be up to seven months with the seat empty.
And you get one person. One skill set, one network, one pair of hands. An excellent paid acquisition lead may be average at search. A brilliant analyst may never have priced a product. Most first hires end up managing agencies anyway, which brings you back to the start.
What is a disadvantage of using an in-house team?
The biggest disadvantage is concentration. Everything the company knows about growth lives in one or two heads. When they leave, it leaves with them. Senior marketing roles do not last forever: Spencer Stuart puts average CMO tenure at S&P 500 companies at 4.1 years (Spencer Stuart, January 2026), and smaller companies rarely do better.
The second disadvantage is range. An in-house team only knows what it has seen. It does not see what is working across ten other companies this quarter. That is exactly what agencies and fractional leaders bring, and why most in-house teams still buy outside help.
Who is accountable for results in each model?
This is the question that matters most, and the one sales conversations avoid.
- The fractional CMO is accountable for the quality of the plan. If the plan is right and execution fails, that is usually somebody else's problem on paper.
- The agency is accountable for its deliverables and its channel metrics. It will rarely sign up to your revenue, because it does not control your pricing, your site or your product.
- The in-house hire is accountable for the number, but often without the team or budget to move it, at least for the first year.
Here is a simple test to run on any of the three. Ask: "Which one number will you own? Where is it today, with the source? Where will it be in 90 days, and what happens if it is not?" A serious answer names one number and a date. A weak answer names five metrics and a process.
How to choose: a quick decision guide
- You know what works and need volume in one channel: hire a specialist agency, and keep one person internal who owns the brief.
- You have a team that executes but no senior direction: a fractional CMO is a good fit. Make sure they inherit people who will do the work.
- You need someone to build and lead a large team in the building: hire full-time, and budget for the wait.
- Nobody owns the growth number, and nobody is doing the work: none of the three solves this alone. You need an owner who also executes. That is the gap the next section covers.
Common questions
What is the difference between a fractional CMO and an agency?
A fractional CMO is a senior marketing leader who works for you part-time, usually one to three days a week, and sets strategy, budget and priorities. An agency is a team paid to execute a defined scope, such as ads, content or search. Put simply, the fractional CMO writes the plan and the agency runs part of it, which is why many companies keep both.
Is a marketing agency worth it?
An agency is worth it when you already know which channel works, the work is specialist enough that hiring would take too long, and someone inside the company can brief the agency and judge its output. It is rarely worth it when you are really buying strategy, because an agency's advice tends to recommend more of the service it sells.
Should I hire a marketing agency or build in-house?
Build in-house when you need deep context and a long-term team, and can wait: senior marketing searches commonly take two to four months, plus notice periods. Hire an agency when you need specialist execution in a proven channel now. If nobody owns the growth number yet, fix ownership first, because neither model creates it on its own.
What is a disadvantage of using an in-house team?
The main disadvantage is concentration. What the company knows about growth sits in one or two people, and it leaves when they do. Spencer Stuart puts average CMO tenure at S&P 500 companies at 4.1 years (January 2026). In-house teams also see only their own company, so they miss what is working elsewhere, which is why most still buy outside help.
Who is accountable for results in each model?
A fractional CMO is accountable for the quality of the plan. An agency is accountable for its deliverables and channel metrics such as clicks and cost per click, not your revenue. An in-house hire is accountable for the number but often lacks the team to move it. Ask any of them which single number they will own, and by when.
Where a Chief Growth Officer fits
There is a fourth model, and it is the one we built. CGO by ClappX is an outsourced Chief Growth Officer: not an adviser on a day rate and not an agency on a scope, but an owner of the number that also does the work.
It runs on two pillars. Organic growth: we execute, we own the number. Being found in search and in the first answer a buyer sees, site structure, listings, catalogue, content, authority, and tracking that works. Intelligent growth: we advise, you decide. Go-to-market, paid strategy, pricing and positioning, conversion and acquisition cost, retention and new markets.
To be clear about the limits: we do not run ad campaigns or make ad creative. Like a real growth head, we set the paid strategy and direct your agency. So if you need a paid social agency, you still need one. What changes is that someone now owns the brief and the result.
Accountability is written down. In week one, both sides sign a baseline: the number, where it is today, the date and the source. Every change after that is logged and, once its judgement date passes, gets a verdict: kept if it moved the number, rolled back if it did not. We review it together every month. The fee is one flat monthly amount, less than one senior hire, plus a share of organic growth above the signed baseline, agreed after month one. Never a share of paid revenue. Month to month, no lock-in. If the numbers are not moving, stop paying us.
When you should not choose it: if your real need is one person leading a large team every day in the office, hire. If you only need more output in a channel that already works, hire an agency.
Want to see what a Chief Growth Officer would do in your first 30 days? Talk to a founder: human@clappx.com