Founders usually ask this question after something has already gone wrong: an agency retainer that never moved the needle, or a consultant engagement that ended in a deck nobody implemented. The three models solve different problems, and picking the wrong one is the most common reason marketing spend doesn’t convert to revenue.
The three models in one line each
- Consultant: diagnoses one defined problem, hands you recommendations, exits.
- Agency: executes a specific channel or set of channels at volume, needs direction to be effective.
- Fractional CMO: owns marketing strategy and function part-time, sets the direction agencies and consultants need.
Fractional CMO vs agency
An agency is built to execute, not to set strategy. Hand an agency a clear brief and budget, and they’ll run paid ads, produce content, or manage SEO at a scale you couldn’t do internally. Hand an agency a vague goal like “grow revenue,” and results are inconsistent, because nobody on their side owns your business outcomes end to end.
A fractional CMO fills that gap: they set the strategy, define what success looks like, and can direct (or replace) an agency that isn’t delivering. The tradeoff is a fractional CMO usually doesn’t execute campaigns themselves; they need either an in-house team or an agency to do the work.
Use an agency when: you already have direction and just need execution capacity. Use a fractional CMO when: nobody senior is setting direction, or your agency relationships keep underperforming because there’s no accountable owner internally.
Fractional CMO vs consultant
A consultant is scoped to a question, not a function. “Should we expand into this market” or “why is our demo-to-close rate so low” are consultant engagements: bounded, diagnostic, usually a few weeks, ending in a report.
A fractional CMO is scoped to a role. They own marketing outcomes on an ongoing basis, not just a single question, and they’re accountable for what happens after the recommendation, not just the recommendation itself.
Use a consultant when: you have one specific, bounded question and don’t need ongoing leadership. Use a fractional CMO when: you need someone accountable for marketing performance over time, not just a one-time answer.
A quick decision framework
| Your situation | Best fit |
|---|---|
| No one senior owns marketing strategy | Fractional CMO |
| Strategy exists, but execution is missing | Agency |
| One specific question needs an outside, objective answer | Consultant |
| Marketing is broken at the infrastructure level (tracking, funnels, automation), not just the strategy level | Strategic Growth Operator — builds the systems, not just the plan |
That last row is worth calling out: none of the three classic models above are built to implement technical infrastructure themselves. If your problem is broken attribution, no lead scoring, or a funnel that’s never been instrumented, you need someone who builds, not just advises or executes campaigns.
Still not sure which fits? See how to choose a growth consultant or when to hire a growth consultant vs a full-time hire.