"You need both, eventually" is where this usually breaks.
That's the consensus answer, and it's mostly written by fractional CMOs who profit from you buying two things instead of one. Under about $5M in revenue, the sequence matters more than the theory.
Our bias, declared
We're an agency, so weigh this accordingly — but the failure mode we see repeatedly isn't companies choosing wrong between these two, it's companies buying a fractional CMO before they have execution capacity to give one. A strategist with nothing to direct either does the hands-on work themselves, below their pay grade and their day rate, or waits on a team that doesn't exist yet. Most of the fractional CMO engagements we've watched quietly stall land here around month four.
Side by side
| Factor | Marketing agency | Fractional CMO |
|---|---|---|
| Cost | Scoped from your brief — no rate card | $5,000–$15,000/month |
| Who executes the work | The agency's team, directly | Nobody — you still need to staff or buy this separately |
| Strategic ownership | Advises within its scope of work | Owns the full go-to-market strategy |
| Board / investor-facing credibility | Rarely presents to the board | Built to sit in that seat |
| Speed to first execution | Days — the team already exists | Weeks — strategy comes before any output |
| Cross-functional authority | None — no mandate over sales or product | Can direct sales and product on GTM decisions |
| What happens if you only buy one | Work ships, but without a strategic through-line | Strategy exists, but nothing ships without more spend |
Choose marketing agency when
You don't yet have a strategy problem
If nobody's disagreed with your current direction in the last two quarters, you likely have an execution gap, not a strategy gap. Paying $10k/month for direction you already have is the most common waste we see in this decision.
You need output within weeks, not a strategy deck first
An agency starts producing work in the first sprint. A CMO's first month is typically audit and planning — valuable, but it's not revenue yet, and under $5M in revenue that lag is expensive.
Under roughly $5M in revenue
A senior agency strategist can own both strategy and execution for close to the cost of the CMO alone. Splitting the two roles below this size usually means paying twice for coordination overhead you don't need yet.
You need one function to be accountable for results
Split ownership creates a genuine failure mode: the CMO sets direction, the agency executes, and when results miss, each has a credible story for why it was the other side. One accountable owner avoids this entirely.
Choose fractional cmo when
You already have execution capacity but no one directing it
In-house team, an agency, or both — running channels well but without a coherent GTM strategy tying them together. This is the one case a fractional CMO clearly earns their rate: coordinating spend that already exists rather than waiting to justify spend that doesn't.
You need a seat at the board or investor table
Agencies don't typically present growth strategy to your board. If that credibility and cross-functional authority over sales and product is the actual need, that's a CMO's job by design, not an add-on to an agency scope.
You're raising, and investors expect a strategic marketing leader
This is a real, distinct need from execution quality — investors are evaluating whether someone owns the growth thesis, not whether the ads are well-optimized.
You've tried an agency alone and direction was the actual gap
If you've already ruled out execution as the problem — the work was competent but aimed at the wrong target — that's the specific signal a strategic layer, not more execution, is what's missing.
Related questions
Yes, and it works well once you're past the size where the sequencing problem bites — usually north of $5M in revenue, or earlier if you're raising and need the credibility. Below that, buying both at once is the most common way we've seen founders overspend on marketing leadership before the underlying growth motion is proven.
Other comparisons
Services referenced
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