The startup market uses “Head of Growth” to mean everything from performance marketer to mini-CMO. That ambiguity makes hiring expensive.
Head of Growth — typical remit
In the strongest version of the role, a Head of Growth:
- owns a portfolio of acquisition and activation experiments
- works with product and data to ship tests quickly
- improves funnel economics within an agreed strategy
What they usually do not own — unless you explicitly expand the role — is executive positioning decisions, board narrative, pricing and packaging governance, and the political work of stopping pet projects across functions.
Fractional CMO — typical remit
A fractional CMO is closer to senior marketing leadership on a part-time cadence: priorities, narrative, channel choices, reporting rhythm, agency and hire briefs, and alignment with sales and CS.
The value is judgement and system design, not maximum weekly experiment count.
The decision rule I use
Ask whether your bottleneck is throughput or definition.
- If leadership agrees on ICP, motion, and success metrics, but execution is slow → a strong Head of Growth (or specialised leads) is often right.
- If leadership still debates who you sell to, what you claim, or why pipeline quality is uneven → fractional executive leadership usually pays for itself faster.
That maps closely to the signals in founder-led growth bottlenecks.
Overlap and sensible combinations
Mature teams sometimes have both: a fractional CMO setting the system and a Head of Growth running the experiment engine. The failure mode is two owners and no clear decision rights.
If you want a wider menu of options — agency, freelancer, junior marketer, consultant — read compare six growth options.
Cost and commitment
A full-time Head of Growth is still a major hire: salary, equity, ramp, and management overhead. A fractional CMO buys senior time in days per week with a defined commercial shape — see Fractional CMO cost (UK) and vs full-time CMO.
Agencies sit on a different axis entirely: channel execution vs executive ownership — fractional CMO vs agency.
Related reading
- When to hire a fractional CMO after seed
- First 90 days of a fractional CMO
- The right window for a fractional CMO
If you want a direct read on what your company actually needs, book a Growth Audit. Service scope for embedded work is on Fractional CMO.